66135223440 has 800 divisors, whose sum is σ = 272232576000. Its totient is φ = 14669475840.

The previous prime is 66135223423. The next prime is 66135223447. The reversal of 66135223440 is 4432253166.

66135223440 is a `hidden beast` number, since 6 + 61 + 3 + 522 + 34 + 40 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 66135223395 and 66135223404.

It is not an unprimeable number, because it can be changed into a prime (66135223447) by changing a digit.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 138069121 + ... + 138069599.

It is an arithmetic number, because the mean of its divisors is an integer number (340290720).

Almost surely, 2^66135223440 is an apocalyptic number.

66135223440 is a gapful number since it is divisible by the number (60) 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 66135223440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (136116288000).

66135223440 is an abundant number, since it is smaller than the sum of its proper divisors (206097352560).

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

66135223440 is a wasteful number, since it uses less digits than its factorization.

66135223440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 677 (or 662 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 36.

The spelling of 66135223440 in words is "sixty-six billion, one hundred thirty-five million, two hundred twenty-three thousand, four hundred forty".