645942874752 has 480 divisors, whose sum is σ = 2353890924000. Its totient is φ = 174839067648.

The previous prime is 645942874741. The next prime is 645942874769. The reversal of 645942874752 is 257478249546.

645942874752 is a `hidden beast` number, since 6 + 45 + 9 + 42 + 87 + 475 + 2 = 666.

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

It is a self number, because there is not a number n which added to its sum of digits gives 645942874752.

It is an unprimeable number.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 9619149 + ... + 9686067.

It is an arithmetic number, because the mean of its divisors is an integer number (4903939425).

Almost surely, 2^645942874752 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 645942874752, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1176945462000).

645942874752 is an abundant number, since it is smaller than the sum of its proper divisors (1707948049248).

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

645942874752 is a wasteful number, since it uses less digits than its factorization.

645942874752 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66978 (or 66950 counting only the distinct ones).

The product of its digits is 135475200, while the sum is 63.

The spelling of 645942874752 in words is "six hundred forty-five billion, nine hundred forty-two million, eight hundred seventy-four thousand, seven hundred fifty-two".