91324021 has 4 divisors (see below), whose sum is σ = 91472652. Its totient is φ = 91175392.

The previous prime is 91323997. The next prime is 91324031. The reversal of 91324021 is 12042319.

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

It can be written as a sum of positive squares in 2 ways, for example, as 6426225 + 84897796 = 2535^2 + 9214^2 .

It is a cyclic number.

It is not a de Polignac number, because 91324021 - 2⁵ = 91323989 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 91323983 and 91324001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91324031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 73390 + ... + 74623.

It is an arithmetic number, because the mean of its divisors is an integer number (22868163).

Almost surely, 2^91324021 is an apocalyptic number.

It is an amenable number.

91324021 is a deficient number, since it is larger than the sum of its proper divisors (148631).

91324021 is a wasteful number, since it uses less digits than its factorization.

91324021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 148630.

The product of its (nonzero) digits is 432, while the sum is 22.

The square root of 91324021 is about 9556.3602380823. The cubic root of 91324021 is about 450.3273683709.

The spelling of 91324021 in words is "ninety-one million, three hundred twenty-four thousand, twenty-one".