261308656 has 40 divisors (see below), whose sum is σ = 589542624. Its totient is φ = 109873920.

The previous prime is 261308639. The next prime is 261308687. The reversal of 261308656 is 656803162.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16075 + ... + 27946.

Almost surely, 2^261308656 is an apocalyptic number.

It is an amenable number.

261308656 is an abundant number, since it is smaller than the sum of its proper divisors (328233968).

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

261308656 is a wasteful number, since it uses less digits than its factorization.

261308656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44089 (or 44083 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 37.

The square root of 261308656 is about 16165.0442622345. The cubic root of 261308656 is about 639.3194719464.

The spelling of 261308656 in words is "two hundred sixty-one million, three hundred eight thousand, six hundred fifty-six".