91440491 has 4 divisors (see below), whose sum is σ = 91766184. Its totient is φ = 91114800.

The previous prime is 91440449. The next prime is 91440493. The reversal of 91440491 is 19404419.

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 91440491 - 2¹⁴ = 91424107 is a prime.

It is a super-2 number, since 2×91440491² = 16722726788642162, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91440493) 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, 162425 + ... + 162986.

It is an arithmetic number, because the mean of its divisors is an integer number (22941546).

Almost surely, 2^91440491 is an apocalyptic number.

91440491 is a deficient number, since it is larger than the sum of its proper divisors (325693).

91440491 is a wasteful number, since it uses less digits than its factorization.

91440491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 325692.

The product of its (nonzero) digits is 5184, while the sum is 32.

The square root of 91440491 is about 9562.4521436711. The cubic root of 91440491 is about 450.5187285652.

The spelling of 91440491 in words is "ninety-one million, four hundred forty thousand, four hundred ninety-one".