91890931 has 8 divisors (see below), whose sum is σ = 100337328. Its totient is φ = 83460000.

The previous prime is 91890917. The next prime is 91890947. The reversal of 91890931 is 13909819.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 91890931 - 2⁷ = 91890803 is a prime.

It is a super-2 number, since 2×91890931² = 16887886400093522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91890901) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11101 + ... + 17521.

It is an arithmetic number, because the mean of its divisors is an integer number (12542166).

Almost surely, 2^91890931 is an apocalyptic number.

91890931 is a deficient number, since it is larger than the sum of its proper divisors (8446397).

91890931 is a wasteful number, since it uses less digits than its factorization.

91890931 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7733.

The product of its (nonzero) digits is 17496, while the sum is 40.

The square root of 91890931 is about 9585.9757458487. The cubic root of 91890931 is about 451.2572757374.

The spelling of 91890931 in words is "ninety-one million, eight hundred ninety thousand, nine hundred thirty-one".