91778633 has 2 divisors, whose sum is σ = 91778634. Its totient is φ = 91778632.

The previous prime is 91778573. The next prime is 91778651. The reversal of 91778633 is 33687719.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 67699984 + 24078649 = 8228^2 + 4907^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-91778633 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (91778663) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45889316 + 45889317.

It is an arithmetic number, because the mean of its divisors is an integer number (45889317).

Almost surely, 2^91778633 is an apocalyptic number.

It is an amenable number.

91778633 is a deficient number, since it is larger than the sum of its proper divisors (1).

91778633 is an equidigital number, since it uses as much as digits as its factorization.

91778633 is an evil number, because the sum of its binary digits is even.

The product of its digits is 190512, while the sum is 44.

The square root of 91778633 is about 9580.1165441763. The cubic root of 91778633 is about 451.0733767531.

The spelling of 91778633 in words is "ninety-one million, seven hundred seventy-eight thousand, six hundred thirty-three".