66853790640 has 1920 divisors, whose sum is σ = 321536563200. Its totient is φ = 12576964608.

The previous prime is 66853790611. The next prime is 66853790651. The reversal of 66853790640 is 4609735866.

66853790640 is a `hidden beast` number, since 6 + 68 + 537 + 9 + 0 + 6 + 40 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 383 ways as a sum of consecutive naturals, for example, 3518620551 + ... + 3518620569.

It is an arithmetic number, because the mean of its divisors is an integer number (167466960).

Almost surely, 2^66853790640 is an apocalyptic number.

66853790640 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 66853790640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (160768281600).

66853790640 is an abundant number, since it is smaller than the sum of its proper divisors (254682772560).

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

66853790640 is a wasteful number, since it uses less digits than its factorization.

66853790640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 103 (or 66 counting only the distinct ones).

The product of its (nonzero) digits is 6531840, while the sum is 54.

The spelling of 66853790640 in words is "sixty-six billion, eight hundred fifty-three million, seven hundred ninety thousand, six hundred forty".