261351131 has 2 divisors, whose sum is σ = 261351132. Its totient is φ = 261351130.

The previous prime is 261351127. The next prime is 261351151. The reversal of 261351131 is 131153162.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 261351131 - 2² = 261351127 is a prime.

It is a super-2 number, since 2×261351131² = 136608827349958322, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 261351097 and 261351106.

It is not a weakly prime, because it can be changed into another prime (261351151) 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 as a sum of consecutive naturals, namely, 130675565 + 130675566.

It is an arithmetic number, because the mean of its divisors is an integer number (130675566).

Almost surely, 2^261351131 is an apocalyptic number.

261351131 is a deficient number, since it is larger than the sum of its proper divisors (1).

261351131 is an equidigital number, since it uses as much as digits as its factorization.

261351131 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 540, while the sum is 23.

The square root of 261351131 is about 16166.3580004898. The cubic root of 261351131 is about 639.3541099409.

The spelling of 261351131 in words is "two hundred sixty-one million, three hundred fifty-one thousand, one hundred thirty-one".