91090975 has 6 divisors (see below), whose sum is σ = 112952840. Its totient is φ = 72872760.

The previous prime is 91090957. The next prime is 91091023. The reversal of 91090975 is 57909019.

It is not a de Polignac number, because 91090975 - 2¹⁷ = 90959903 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1821795 + ... + 1821844.

Almost surely, 2^91090975 is an apocalyptic number.

91090975 is a deficient number, since it is larger than the sum of its proper divisors (21861865).

91090975 is a wasteful number, since it uses less digits than its factorization.

91090975 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3643649 (or 3643644 counting only the distinct ones).

The product of its (nonzero) digits is 25515, while the sum is 40.

The square root of 91090975 is about 9544.1592086469. The cubic root of 91090975 is about 449.9439847972.

The spelling of 91090975 in words is "ninety-one million, ninety thousand, nine hundred seventy-five".