261356457 has 16 divisors (see below), whose sum is σ = 370071360. Its totient is φ = 163602432.

The previous prime is 261356449. The next prime is 261356479. The reversal of 261356457 is 754653162.

It is not a de Polignac number, because 261356457 - 2³ = 261356449 is a prime.

It is not an unprimeable number, because it can be changed into a prime (261356437) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13848 + ... + 26729.

It is an arithmetic number, because the mean of its divisors is an integer number (23129460).

Almost surely, 2^261356457 is an apocalyptic number.

It is an amenable number.

261356457 is a deficient number, since it is larger than the sum of its proper divisors (108714903).

261356457 is a wasteful number, since it uses less digits than its factorization.

261356457 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40712.

The product of its digits is 151200, while the sum is 39.

The square root of 261356457 is about 16166.5227244451. The cubic root of 261356457 is about 639.3584529830.

The spelling of 261356457 in words is "two hundred sixty-one million, three hundred fifty-six thousand, four hundred fifty-seven".