261534257551731 has 16 divisors (see below), whose sum is σ = 348846284256768. Its totient is φ = 174289204656000.

The previous prime is 261534257551681. The next prime is 261534257551733. The reversal of 261534257551731 is 137155752435162.

It is not a de Polignac number, because 261534257551731 - 2¹³ = 261534257543539 is a prime.

It is a super-2 number, since 2×261534257551731² (a number of 30 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (261534257551733) 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, 324886530 + ... + 325690536.

It is an arithmetic number, because the mean of its divisors is an integer number (21802892766048).

Almost surely, 2^{261534257551731} is an apocalyptic number.

261534257551731 is a deficient number, since it is larger than the sum of its proper divisors (87312026705037).

261534257551731 is a wasteful number, since it uses less digits than its factorization.

261534257551731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 845522.

The product of its digits is 26460000, while the sum is 57.

The spelling of 261534257551731 in words is "two hundred sixty-one trillion, five hundred thirty-four billion, two hundred fifty-seven million, five hundred fifty-one thousand, seven hundred thirty-one".