645795236772 has 432 divisors, whose sum is σ = 2134620633600. Its totient is φ = 163322127360.

The previous prime is 645795236663. The next prime is 645795236777. The reversal of 645795236772 is 277632597546.

It is a happy number.

645795236772 is a `hidden beast` number, since 6 + 4 + 579 + 52 + 3 + 6 + 7 + 7 + 2 = 666.

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

It is not an unprimeable number, because it can be changed into a prime (645795236777) by changing a digit.

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 143 ways as a sum of consecutive naturals, for example, 30120168 + ... + 30141600.

Almost surely, 2^645795236772 is an apocalyptic number.

645795236772 is a gapful number since it is divisible by the number (62) 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 645795236772, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1067310316800).

645795236772 is an abundant number, since it is smaller than the sum of its proper divisors (1488825396828).

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

645795236772 is a wasteful number, since it uses less digits than its factorization.

645795236772 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21536 (or 21524 counting only the distinct ones).

The product of its digits is 133358400, while the sum is 63.

The spelling of 645795236772 in words is "six hundred forty-five billion, seven hundred ninety-five million, two hundred thirty-six thousand, seven hundred seventy-two".