261319087 has 16 divisors (see below), whose sum is σ = 287396640. Its totient is φ = 236500992.

The previous prime is 261319033. The next prime is 261319099. The reversal of 261319087 is 780913162.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261319087 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 (261319687) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 138583 + ... + 140455.

It is an arithmetic number, because the mean of its divisors is an integer number (17962290).

Almost surely, 2^261319087 is an apocalyptic number.

261319087 is a deficient number, since it is larger than the sum of its proper divisors (26077553).

261319087 is a wasteful number, since it uses less digits than its factorization.

261319087 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2202.

The product of its (nonzero) digits is 18144, while the sum is 37.

The square root of 261319087 is about 16165.3668996407. The cubic root of 261319087 is about 639.3279786843.

The spelling of 261319087 in words is "two hundred sixty-one million, three hundred nineteen thousand, eighty-seven".