261623870836 has 12 divisors (see below), whose sum is σ = 470215876228. Its totient is φ = 127276477632.

The previous prime is 261623870813. The next prime is 261623870863. The reversal of 261623870836 is 638078326162.

It can be written as a sum of positive squares in 2 ways, for example, as 214119052900 + 47504817936 = 462730^2 + 217956^2 .

It is a super-2 number, since 2×261623870836² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 883864281 + ... + 883864576.

Almost surely, 2^261623870836 is an apocalyptic number.

It is an amenable number.

261623870836 is a deficient number, since it is larger than the sum of its proper divisors (208592005392).

261623870836 is a wasteful number, since it uses less digits than its factorization.

261623870836 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1767728898 (or 1767728896 counting only the distinct ones).

The product of its (nonzero) digits is 3483648, while the sum is 52.

The spelling of 261623870836 in words is "two hundred sixty-one billion, six hundred twenty-three million, eight hundred seventy thousand, eight hundred thirty-six".