91977929 has 2 divisors, whose sum is σ = 91977930. Its totient is φ = 91977928.

The previous prime is 91977913. The next prime is 91977931. The reversal of 91977929 is 92977919.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 79566400 + 12411529 = 8920^2 + 3523^2 .

It is an emirp because it is prime and its reverse (92977919) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 91977929 - 2⁴ = 91977913 is a prime.

It is a Sophie Germain prime.

Together with 91977931, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (91977959) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45988964 + 45988965.

It is an arithmetic number, because the mean of its divisors is an integer number (45988965).

Almost surely, 2^91977929 is an apocalyptic number.

It is an amenable number.

91977929 is a deficient number, since it is larger than the sum of its proper divisors (1).

91977929 is an equidigital number, since it uses as much as digits as its factorization.

91977929 is an evil number, because the sum of its binary digits is even.

The product of its digits is 642978, while the sum is 53.

The square root of 91977929 is about 9590.5124472053. The cubic root of 91977929 is about 451.3996405214.

The spelling of 91977929 in words is "ninety-one million, nine hundred seventy-seven thousand, nine hundred twenty-nine".