91440168737 has 2 divisors, whose sum is σ = 91440168738. Its totient is φ = 91440168736.

The previous prime is 91440168731. The next prime is 91440168739. The reversal of 91440168737 is 73786104419.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 79454079376 + 11986089361 = 281876^2 + 109481^2 .

It is a cyclic number.

It is not a de Polignac number, because 91440168737 - 2²⁶ = 91373059873 is a prime.

It is a super-2 number, since 2×91440168737² (a number of 23 digits) contains 22 as substring.

Together with 91440168739, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (91440168731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45720084368 + 45720084369.

It is an arithmetic number, because the mean of its divisors is an integer number (45720084369).

Almost surely, 2^91440168737 is an apocalyptic number.

It is an amenable number.

91440168737 is a deficient number, since it is larger than the sum of its proper divisors (1).

91440168737 is an equidigital number, since it uses as much as digits as its factorization.

91440168737 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1016064, while the sum is 50.

The spelling of 91440168737 in words is "ninety-one billion, four hundred forty million, one hundred sixty-eight thousand, seven hundred thirty-seven".