661510256 has 40 divisors (see below), whose sum is σ = 1480445424. Its totient is φ = 282997760.

The previous prime is 661510247. The next prime is 661510279. The reversal of 661510256 is 652015166.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 107555 + ... + 113538.

Almost surely, 2^661510256 is an apocalyptic number.

It is an amenable number.

661510256 is an abundant number, since it is smaller than the sum of its proper divisors (818935168).

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

661510256 is a wasteful number, since it uses less digits than its factorization.

661510256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 221129 (or 221123 counting only the distinct ones).

The product of its (nonzero) digits is 10800, while the sum is 32.

The square root of 661510256 is about 25719.8416791395. The cubic root of 661510256 is about 871.3223630276.

The spelling of 661510256 in words is "six hundred sixty-one million, five hundred ten thousand, two hundred fifty-six".