91009231 has 4 divisors (see below), whose sum is σ = 91067472. Its totient is φ = 90950992.

The previous prime is 91009213. The next prime is 91009241. The reversal of 91009231 is 13290019.

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 91009231 - 2¹¹ = 91007183 is a prime.

It is a super-2 number, since 2×91009231² = 16565360254422722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 91009196 and 91009205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91009241) 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, 26710 + ... + 29923.

It is an arithmetic number, because the mean of its divisors is an integer number (22766868).

Almost surely, 2^91009231 is an apocalyptic number.

91009231 is a deficient number, since it is larger than the sum of its proper divisors (58241).

91009231 is a wasteful number, since it uses less digits than its factorization.

91009231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58240.

The product of its (nonzero) digits is 486, while the sum is 25.

The square root of 91009231 is about 9539.8758377664. The cubic root of 91009231 is about 449.8093529867.

The spelling of 91009231 in words is "ninety-one million, nine thousand, two hundred thirty-one".