66090172573656 has 576 divisors, whose sum is σ = 236123659699200. Its totient is φ = 16315278819840.

The previous prime is 66090172573643. The next prime is 66090172573669. The reversal of 66090172573656 is 65637527109066.

66090172573656 is a `hidden beast` number, since 6 + 6 + 0 + 9 + 0 + 1 + 7 + 2 + 573 + 6 + 56 = 666.

66090172573656 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (66090172573643) and next prime (66090172573669).

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a junction number, because it is equal to n+sod(n) for n = 66090172573593 and 66090172573602.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 220063165 + ... + 220363283.

It is an arithmetic number, because the mean of its divisors is an integer number (409936909200).

Almost surely, 2^{66090172573656} is an apocalyptic number.

66090172573656 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66090172573656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (118061829849600).

66090172573656 is an abundant number, since it is smaller than the sum of its proper divisors (170033487125544).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66090172573656 is a wasteful number, since it uses less digits than its factorization.

66090172573656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 300340 (or 300322 counting only the distinct ones).

The product of its (nonzero) digits is 85730400, while the sum is 63.

The spelling of 66090172573656 in words is "sixty-six trillion, ninety billion, one hundred seventy-two million, five hundred seventy-three thousand, six hundred fifty-six".