261647406 has 24 divisors (see below), whose sum is σ = 567201960. Its totient is φ = 87169776.

The previous prime is 261647377. The next prime is 261647411. The reversal of 261647406 is 604746162.

261647406 is a `hidden beast` number, since 2 + 6 + 1 + 647 + 4 + 0 + 6 = 666.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 59305 + ... + 63563.

It is an arithmetic number, because the mean of its divisors is an integer number (23633415).

Almost surely, 2^261647406 is an apocalyptic number.

261647406 is an abundant number, since it is smaller than the sum of its proper divisors (305554554).

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

261647406 is a wasteful number, since it uses less digits than its factorization.

261647406 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7680 (or 7677 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 36.

The square root of 261647406 is about 16175.5187242944. The cubic root of 261647406 is about 639.5956153111.

The spelling of 261647406 in words is "two hundred sixty-one million, six hundred forty-seven thousand, four hundred six".