91938779 has 2 divisors, whose sum is σ = 91938780. Its totient is φ = 91938778.

The previous prime is 91938733. The next prime is 91938799. The reversal of 91938779 is 97783919.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 91938779 - 2¹² = 91934683 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 91938779.

It is not a weakly prime, because it can be changed into another prime (91938719) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45969389 + 45969390.

It is an arithmetic number, because the mean of its divisors is an integer number (45969390).

Almost surely, 2^91938779 is an apocalyptic number.

91938779 is a deficient number, since it is larger than the sum of its proper divisors (1).

91938779 is an equidigital number, since it uses as much as digits as its factorization.

91938779 is an evil number, because the sum of its binary digits is even.

The product of its digits is 857304, while the sum is 53.

The square root of 91938779 is about 9588.4711502929. The cubic root of 91938779 is about 451.3355860101.

The spelling of 91938779 in words is "ninety-one million, nine hundred thirty-eight thousand, seven hundred seventy-nine".