91477173496921 has 2 divisors, whose sum is σ = 91477173496922. Its totient is φ = 91477173496920.

The previous prime is 91477173496879. The next prime is 91477173496937. The reversal of 91477173496921 is 12969437177419.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 83561171792400 + 7916001704521 = 9141180^2 + 2813539^2 .

It is a cyclic number.

It is not a de Polignac number, because 91477173496921 - 2¹⁷ = 91477173365849 is a prime.

It is not a weakly prime, because it can be changed into another prime (91477173496981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45738586748460 + 45738586748461.

It is an arithmetic number, because the mean of its divisors is an integer number (45738586748461).

Almost surely, 2^{91477173496921} is an apocalyptic number.

It is an amenable number.

91477173496921 is a deficient number, since it is larger than the sum of its proper divisors (1).

91477173496921 is an equidigital number, since it uses as much as digits as its factorization.

91477173496921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 144027072, while the sum is 70.

The spelling of 91477173496921 in words is "ninety-one trillion, four hundred seventy-seven billion, one hundred seventy-three million, four hundred ninety-six thousand, nine hundred twenty-one".