91395979973 has 2 divisors, whose sum is σ = 91395979974. Its totient is φ = 91395979972.

The previous prime is 91395979951. The next prime is 91395980063. The reversal of 91395979973 is 37997959319.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 89004965569 + 2391014404 = 298337^2 + 48898^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-91395979973 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 91395979897 and 91395979906.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91395979573) 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, 45697989986 + 45697989987.

It is an arithmetic number, because the mean of its divisors is an integer number (45697989987).

Almost surely, 2^91395979973 is an apocalyptic number.

It is an amenable number.

91395979973 is a deficient number, since it is larger than the sum of its proper divisors (1).

91395979973 is an equidigital number, since it uses as much as digits as its factorization.

91395979973 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 130203045, while the sum is 71.

The spelling of 91395979973 in words is "ninety-one billion, three hundred ninety-five million, nine hundred seventy-nine thousand, nine hundred seventy-three".