261631235413 has 2 divisors, whose sum is σ = 261631235414. Its totient is φ = 261631235412.

The previous prime is 261631235311. The next prime is 261631235447. The reversal of 261631235413 is 314532136162.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 141043811364 + 120587424049 = 375558^2 + 347257^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261631235413 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261631235813) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130815617706 + 130815617707.

It is an arithmetic number, because the mean of its divisors is an integer number (130815617707).

Almost surely, 2^261631235413 is an apocalyptic number.

It is an amenable number.

261631235413 is a deficient number, since it is larger than the sum of its proper divisors (1).

261631235413 is an equidigital number, since it uses as much as digits as its factorization.

261631235413 is an evil number, because the sum of its binary digits is even.

The product of its digits is 77760, while the sum is 37.

The spelling of 261631235413 in words is "two hundred sixty-one billion, six hundred thirty-one million, two hundred thirty-five thousand, four hundred thirteen".