261516465 has 128 divisors (see below), whose sum is σ = 560332800. Its totient is φ = 113218560.

The previous prime is 261516439. The next prime is 261516467. The reversal of 261516465 is 564615162.

261516465 is a `hidden beast` number, since 2 + 6 + 1 + 5 + 1 + 646 + 5 = 666.

It is not a de Polignac number, because 261516465 - 2⁵ = 261516433 is a prime.

It is a super-2 number, since 2×261516465² = 136781722932192450, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (261516467) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 2314249 + ... + 2314361.

It is an arithmetic number, because the mean of its divisors is an integer number (4377600).

Almost surely, 2^261516465 is an apocalyptic number.

It is an amenable number.

261516465 is an abundant number, since it is smaller than the sum of its proper divisors (298816335).

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

261516465 is a wasteful number, since it uses less digits than its factorization.

261516465 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 244 (or 238 counting only the distinct ones).

The product of its digits is 43200, while the sum is 36.

The square root of 261516465 is about 16171.4707123378. The cubic root of 261516465 is about 639.4889026613.

The spelling of 261516465 in words is "two hundred sixty-one million, five hundred sixteen thousand, four hundred sixty-five".