645648156 has 144 divisors (see below), whose sum is σ = 1740263616. Its totient is φ = 201600000.

The previous prime is 645648149. The next prime is 645648161. The reversal of 645648156 is 651846546.

645648156 is a `hidden beast` number, since 6 + 4 + 564 + 81 + 5 + 6 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 6392506 + ... + 6392606.

It is an arithmetic number, because the mean of its divisors is an integer number (12085164).

Almost surely, 2^645648156 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 645648156, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (870131808).

645648156 is an abundant number, since it is smaller than the sum of its proper divisors (1094615460).

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

645648156 is a wasteful number, since it uses less digits than its factorization.

645648156 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 284 (or 279 counting only the distinct ones).

The product of its digits is 691200, while the sum is 45.

The square root of 645648156 is about 25409.6075530497. The cubic root of 645648156 is about 864.3015761794.

The spelling of 645648156 in words is "six hundred forty-five million, six hundred forty-eight thousand, one hundred fifty-six".