91415571761 has 2 divisors, whose sum is σ = 91415571762. Its totient is φ = 91415571760.

The previous prime is 91415571757. The next prime is 91415571851. The reversal of 91415571761 is 16717551419.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 81741669025 + 9673902736 = 285905^2 + 98356^2 .

It is a cyclic number.

It is not a de Polignac number, because 91415571761 - 2² = 91415571757 is a prime.

It is a super-2 number, since 2×91415571761² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (91415571461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45707785880 + 45707785881.

It is an arithmetic number, because the mean of its divisors is an integer number (45707785881).

Almost surely, 2^91415571761 is an apocalyptic number.

It is an amenable number.

91415571761 is a deficient number, since it is larger than the sum of its proper divisors (1).

91415571761 is an equidigital number, since it uses as much as digits as its factorization.

91415571761 is an evil number, because the sum of its binary digits is even.

The product of its digits is 264600, while the sum is 47.

The spelling of 91415571761 in words is "ninety-one billion, four hundred fifteen million, five hundred seventy-one thousand, seven hundred sixty-one".