91624321 has 4 divisors (see below), whose sum is σ = 94100692. Its totient is φ = 89147952.

The previous prime is 91624303. The next prime is 91624331. The reversal of 91624321 is 12342619.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12342619 = 31 ⋅398149.

It can be written as a sum of positive squares in 2 ways, for example, as 79121025 + 12503296 = 8895^2 + 3536^2 .

It is a cyclic number.

It is not a de Polignac number, because 91624321 - 2¹⁵ = 91591553 is a prime.

It is a super-2 number, since 2×91624321² = 16790032397422082, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 91624321.

It is not an unprimeable number, because it can be changed into a prime (91624331) 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, 1238130 + ... + 1238203.

It is an arithmetic number, because the mean of its divisors is an integer number (23525173).

Almost surely, 2^91624321 is an apocalyptic number.

It is an amenable number.

91624321 is a deficient number, since it is larger than the sum of its proper divisors (2476371).

91624321 is a wasteful number, since it uses less digits than its factorization.

91624321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2476370.

The product of its digits is 2592, while the sum is 28.

The square root of 91624321 is about 9572.0593917923. The cubic root of 91624321 is about 450.8204308701.

The spelling of 91624321 in words is "ninety-one million, six hundred twenty-four thousand, three hundred twenty-one".