91790057 has 4 divisors (see below), whose sum is σ = 92648016. Its totient is φ = 90932100.

The previous prime is 91790053. The next prime is 91790059. The reversal of 91790057 is 75009719.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 75009719 = 1709 ⋅43891.

It is a cyclic number.

It is not a de Polignac number, because 91790057 - 2² = 91790053 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 91790057.

It is not an unprimeable number, because it can be changed into a prime (91790051) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 428819 + ... + 429032.

It is an arithmetic number, because the mean of its divisors is an integer number (23162004).

Almost surely, 2^91790057 is an apocalyptic number.

It is an amenable number.

91790057 is a deficient number, since it is larger than the sum of its proper divisors (857959).

91790057 is a wasteful number, since it uses less digits than its factorization.

91790057 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 857958.

The product of its (nonzero) digits is 19845, while the sum is 38.

The square root of 91790057 is about 9580.7127605414. The cubic root of 91790057 is about 451.0920915247.

The spelling of 91790057 in words is "ninety-one million, seven hundred ninety thousand, fifty-seven".