261552631 has 2 divisors, whose sum is σ = 261552632. Its totient is φ = 261552630.

The previous prime is 261552601. The next prime is 261552677. The reversal of 261552631 is 136255162.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261552631 is a prime.

It is a super-2 number, since 2×261552631² = 136819557566044322, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 261552593 and 261552602.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261552601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130776315 + 130776316.

It is an arithmetic number, because the mean of its divisors is an integer number (130776316).

Almost surely, 2^261552631 is an apocalyptic number.

261552631 is a deficient number, since it is larger than the sum of its proper divisors (1).

261552631 is an equidigital number, since it uses as much as digits as its factorization.

261552631 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10800, while the sum is 31.

The square root of 261552631 is about 16172.5888774803. The cubic root of 261552631 is about 639.5183803331.

The spelling of 261552631 in words is "two hundred sixty-one million, five hundred fifty-two thousand, six hundred thirty-one".