261380751913 has 2 divisors, whose sum is σ = 261380751914. Its totient is φ = 261380751912.

The previous prime is 261380751803. The next prime is 261380751941. The reversal of 261380751913 is 319157083162.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 202502700009 + 58878051904 = 450003^2 + 242648^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261380751913 is a prime.

It is not a weakly prime, because it can be changed into another prime (261380751943) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130690375956 + 130690375957.

It is an arithmetic number, because the mean of its divisors is an integer number (130690375957).

Almost surely, 2^261380751913 is an apocalyptic number.

It is an amenable number.

261380751913 is a deficient number, since it is larger than the sum of its proper divisors (1).

261380751913 is an equidigital number, since it uses as much as digits as its factorization.

261380751913 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 272160, while the sum is 46.

The spelling of 261380751913 in words is "two hundred sixty-one billion, three hundred eighty million, seven hundred fifty-one thousand, nine hundred thirteen".