66855651264 has 56 divisors (see below), whose sum is σ = 196543239120. Its totient is φ = 22285216512.

The previous prime is 66855651221. The next prime is 66855651271. The reversal of 66855651264 is 46215655866.

66855651264 is a `hidden beast` number, since 6 + 6 + 8 + 5 + 565 + 12 + 64 = 666.

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

It is a self number, because there is not a number n which added to its sum of digits gives 66855651264.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19343079 + ... + 19346534.

Almost surely, 2^66855651264 is an apocalyptic number.

66855651264 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

66855651264 is an abundant number, since it is smaller than the sum of its proper divisors (129687587856).

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

66855651264 is a wasteful number, since it uses less digits than its factorization.

66855651264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38689634 (or 38689618 counting only the distinct ones).

The product of its digits is 10368000, while the sum is 54.

The spelling of 66855651264 in words is "sixty-six billion, eight hundred fifty-five million, six hundred fifty-one thousand, two hundred sixty-four".