261689626627 has 24 divisors (see below), whose sum is σ = 309960928368. Its totient is φ = 219463379520.

The previous prime is 261689626591. The next prime is 261689626637. The reversal of 261689626627 is 726626986162.

It is not a de Polignac number, because 261689626627 - 2²³ = 261681238019 is a prime.

It is not an unprimeable number, because it can be changed into a prime (261689626637) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2524188 + ... + 2625814.

It is an arithmetic number, because the mean of its divisors is an integer number (12915038682).

Almost surely, 2^261689626627 is an apocalyptic number.

261689626627 is a deficient number, since it is larger than the sum of its proper divisors (48271301741).

261689626627 is a wasteful number, since it uses less digits than its factorization.

261689626627 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 103299 (or 103288 counting only the distinct ones).

The product of its digits is 31352832, while the sum is 61.

The spelling of 261689626627 in words is "two hundred sixty-one billion, six hundred eighty-nine million, six hundred twenty-six thousand, six hundred twenty-seven".