261220520164 has 12 divisors (see below), whose sum is σ = 457150040704. Its totient is φ = 130606222824.

The previous prime is 261220520161. The next prime is 261220520173. The reversal of 261220520164 is 461025022162.

261220520164 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (261220520161) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 861324 + ... + 1124419.

Almost surely, 2^261220520164 is an apocalyptic number.

It is an amenable number.

261220520164 is a deficient number, since it is larger than the sum of its proper divisors (195929520540).

261220520164 is a wasteful number, since it uses less digits than its factorization.

261220520164 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2018634 (or 2018632 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 31.

The spelling of 261220520164 in words is "two hundred sixty-one billion, two hundred twenty million, five hundred twenty thousand, one hundred sixty-four".