645593256 has 384 divisors, whose sum is σ = 2339850240. Its totient is φ = 155865600.

The previous prime is 645593243. The next prime is 645593261. The reversal of 645593256 is 652395546.

645593256 is a `hidden beast` number, since 6 + 4 + 5 + 593 + 2 + 56 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 7778191 + ... + 7778273.

It is an arithmetic number, because the mean of its divisors is an integer number (6093360).

Almost surely, 2^645593256 is an apocalyptic number.

645593256 is a gapful number since it is divisible by the number (66) 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 645593256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1169925120).

645593256 is an abundant number, since it is smaller than the sum of its proper divisors (1694256984).

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

645593256 is a wasteful number, since it uses less digits than its factorization.

645593256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 197 (or 190 counting only the distinct ones).

The product of its digits is 972000, while the sum is 45.

The square root of 645593256 is about 25408.5272300462. The cubic root of 645593256 is about 864.2770780576.

The spelling of 645593256 in words is "six hundred forty-five million, five hundred ninety-three thousand, two hundred fifty-six".