90391031 has 4 divisors (see below), whose sum is σ = 92493192. Its totient is φ = 88288872.

The previous prime is 90390997. The next prime is 90391051. The reversal of 90391031 is 13019309.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 90391031 - 2⁶ = 90390967 is a prime.

It is a super-2 number, since 2×90391031² = 16341076970485922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90391051) 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, 1051016 + ... + 1051101.

It is an arithmetic number, because the mean of its divisors is an integer number (23123298).

Almost surely, 2^90391031 is an apocalyptic number.

90391031 is a deficient number, since it is larger than the sum of its proper divisors (2102161).

90391031 is a wasteful number, since it uses less digits than its factorization.

90391031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2102160.

The product of its (nonzero) digits is 729, while the sum is 26.

The square root of 90391031 is about 9507.4197866719. The cubic root of 90391031 is about 448.7885622104.

The spelling of 90391031 in words is "ninety million, three hundred ninety-one thousand, thirty-one".