261477902655 has 40 divisors (see below), whose sum is σ = 468770434704. Its totient is φ = 139440873600.

The previous prime is 261477902641. The next prime is 261477902671. The reversal of 261477902655 is 556209774162.

It is a happy number.

261477902655 is a `hidden beast` number, since 2 + 61 + 477 + 90 + 26 + 5 + 5 = 666.

It is not a de Polignac number, because 261477902655 - 2¹⁰ = 261477901631 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 4947520 + ... + 5000090.

Almost surely, 2^261477902655 is an apocalyptic number.

261477902655 is a deficient number, since it is larger than the sum of its proper divisors (207292532049).

261477902655 is a wasteful number, since it uses less digits than its factorization.

261477902655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64869 (or 64860 counting only the distinct ones).

The product of its (nonzero) digits is 6350400, while the sum is 54.

The spelling of 261477902655 in words is "two hundred sixty-one billion, four hundred seventy-seven million, nine hundred two thousand, six hundred fifty-five".