645854256 has 80 divisors (see below), whose sum is σ = 1863496800. Its totient is φ = 214163712.

The previous prime is 645854239. The next prime is 645854257. The reversal of 645854256 is 652458546.

645854256 is a `hidden beast` number, since 6 + 4 + 58 + 542 + 56 = 666.

It is not an unprimeable number, because it can be changed into a prime (645854257) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 81310 + ... + 88898.

It is an arithmetic number, because the mean of its divisors is an integer number (23293710).

Almost surely, 2^645854256 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 645854256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (931748400).

645854256 is an abundant number, since it is smaller than the sum of its proper divisors (1217642544).

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

645854256 is a wasteful number, since it uses less digits than its factorization.

645854256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7803 (or 7791 counting only the distinct ones).

The product of its digits is 1152000, while the sum is 45.

The square root of 645854256 is about 25413.6627820549. The cubic root of 645854256 is about 864.3935321477.

The spelling of 645854256 in words is "six hundred forty-five million, eight hundred fifty-four thousand, two hundred fifty-six".