91931923 has 2 divisors, whose sum is σ = 91931924. Its totient is φ = 91931922.

The previous prime is 91931867. The next prime is 91931933. The reversal of 91931923 is 32913919.

It is a strong prime.

It is an emirp because it is prime and its reverse (32913919) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 91931923 - 2¹³ = 91923731 is a prime.

It is not a weakly prime, because it can be changed into another prime (91931933) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45965961 + 45965962.

It is an arithmetic number, because the mean of its divisors is an integer number (45965962).

Almost surely, 2^91931923 is an apocalyptic number.

91931923 is a deficient number, since it is larger than the sum of its proper divisors (1).

91931923 is an equidigital number, since it uses as much as digits as its factorization.

91931923 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13122, while the sum is 37.

The square root of 91931923 is about 9588.1136309495. The cubic root of 91931923 is about 451.3243668280.

The spelling of 91931923 in words is "ninety-one million, nine hundred thirty-one thousand, nine hundred twenty-three".