91992421 has 2 divisors, whose sum is σ = 91992422. Its totient is φ = 91992420.

The previous prime is 91992359. The next prime is 91992463. The reversal of 91992421 is 12429919.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 90516196 + 1476225 = 9514^2 + 1215^2 .

It is a cyclic number.

It is not a de Polignac number, because 91992421 - 2⁷ = 91992293 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91992521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45996210 + 45996211.

It is an arithmetic number, because the mean of its divisors is an integer number (45996211).

Almost surely, 2^91992421 is an apocalyptic number.

It is an amenable number.

91992421 is a deficient number, since it is larger than the sum of its proper divisors (1).

91992421 is an equidigital number, since it uses as much as digits as its factorization.

91992421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11664, while the sum is 37.

The square root of 91992421 is about 9591.2679558023. The cubic root of 91992421 is about 451.4233467160.

The spelling of 91992421 in words is "ninety-one million, nine hundred ninety-two thousand, four hundred twenty-one".