645355875168 has 216 divisors, whose sum is σ = 1962484851600. Its totient is φ = 201119846400.

The previous prime is 645355875127. The next prime is 645355875179. The reversal of 645355875168 is 861578553546.

645355875168 is a `hidden beast` number, since 6 + 4 + 5 + 3 + 558 + 75 + 1 + 6 + 8 = 666.

It is a super-2 number, since 2×645355875168² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 12542358 + ... + 12593706.

Almost surely, 2^645355875168 is an apocalyptic number.

645355875168 is a gapful number since it is divisible by the number (68) 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 645355875168, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (981242425800).

645355875168 is an abundant number, since it is smaller than the sum of its proper divisors (1317128976432).

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

645355875168 is a wasteful number, since it uses less digits than its factorization.

645355875168 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51550 (or 51522 counting only the distinct ones).

The product of its digits is 120960000, while the sum is 63.

The spelling of 645355875168 in words is "six hundred forty-five billion, three hundred fifty-five million, eight hundred seventy-five thousand, one hundred sixty-eight".