291751649261 has 2 divisors, whose sum is σ = 291751649262. Its totient is φ = 291751649260.

The previous prime is 291751649249. The next prime is 291751649327. The reversal of 291751649261 is 162946157192.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 279834652036 + 11916997225 = 528994^2 + 109165^2 .

It is a cyclic number.

It is not a de Polignac number, because 291751649261 - 2³⁸ = 16873742317 is a prime.

It is a super-2 number, since 2×291751649261² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (291751249261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 145875824630 + 145875824631.

It is an arithmetic number, because the mean of its divisors is an integer number (145875824631).

Almost surely, 2^291751649261 is an apocalyptic number.

It is an amenable number.

291751649261 is a deficient number, since it is larger than the sum of its proper divisors (1).

291751649261 is an equidigital number, since it uses as much as digits as its factorization.

291751649261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1632960, while the sum is 53.

The spelling of 291751649261 in words is "two hundred ninety-one billion, seven hundred fifty-one million, six hundred forty-nine thousand, two hundred sixty-one".