261225564 has 24 divisors (see below), whose sum is σ = 609951888. Its totient is φ = 87014400.

The previous prime is 261225557. The next prime is 261225581. The reversal of 261225564 is 465522162.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12414 + ... + 26010.

It is an arithmetic number, because the mean of its divisors is an integer number (25414662).

Almost surely, 2^261225564 is an apocalyptic number.

It is an amenable number.

261225564 is an abundant number, since it is smaller than the sum of its proper divisors (348726324).

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

261225564 is a wasteful number, since it uses less digits than its factorization.

261225564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15205 (or 15203 counting only the distinct ones).

The product of its digits is 28800, while the sum is 33.

The square root of 261225564 is about 16162.4739442945. The cubic root of 261225564 is about 639.2517002851.

The spelling of 261225564 in words is "two hundred sixty-one million, two hundred twenty-five thousand, five hundred sixty-four".