261284815 has 32 divisors (see below), whose sum is σ = 365518656. Its totient is φ = 177192960.

The previous prime is 261284773. The next prime is 261284819. The reversal of 261284815 is 518482162.

It is not a de Polignac number, because 261284815 - 2¹¹ = 261282767 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261284819) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 104419 + ... + 106891.

It is an arithmetic number, because the mean of its divisors is an integer number (11422458).

Almost surely, 2^261284815 is an apocalyptic number.

261284815 is a deficient number, since it is larger than the sum of its proper divisors (104233841).

261284815 is a wasteful number, since it uses less digits than its factorization.

261284815 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2619.

The product of its digits is 30720, while the sum is 37.

The square root of 261284815 is about 16164.3068208940. The cubic root of 261284815 is about 639.3000281728.

The spelling of 261284815 in words is "two hundred sixty-one million, two hundred eighty-four thousand, eight hundred fifteen".