261639869204 has 24 divisors (see below), whose sum is σ = 523815391680. Its totient is φ = 112016589696.

The previous prime is 261639869147. The next prime is 261639869219. The reversal of 261639869204 is 402968936162.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 261639869204.

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, 4754774 + ... + 4809485.

It is an arithmetic number, because the mean of its divisors is an integer number (21825641320).

Almost surely, 2^261639869204 is an apocalyptic number.

It is an amenable number.

261639869204 is an abundant number, since it is smaller than the sum of its proper divisors (262175522476).

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

261639869204 is a wasteful number, since it uses less digits than its factorization.

261639869204 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9565247 (or 9565245 counting only the distinct ones).

The product of its (nonzero) digits is 6718464, while the sum is 56.

The spelling of 261639869204 in words is "two hundred sixty-one billion, six hundred thirty-nine million, eight hundred sixty-nine thousand, two hundred four".