261963564 has 24 divisors (see below), whose sum is σ = 643419840. Its totient is φ = 82725264.

The previous prime is 261963551. The next prime is 261963593. The reversal of 261963564 is 465369162.

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, 574254 + ... + 574709.

It is an arithmetic number, because the mean of its divisors is an integer number (26809160).

Almost surely, 2^261963564 is an apocalyptic number.

It is an amenable number.

261963564 is an abundant number, since it is smaller than the sum of its proper divisors (381456276).

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

261963564 is a wasteful number, since it uses less digits than its factorization.

261963564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1148989 (or 1148987 counting only the distinct ones).

The product of its digits is 233280, while the sum is 42.

The square root of 261963564 is about 16185.2885053063. The cubic root of 261963564 is about 639.8531271042.

The spelling of 261963564 in words is "two hundred sixty-one million, nine hundred sixty-three thousand, five hundred sixty-four".