91432021 has 4 divisors (see below), whose sum is σ = 91796544. Its totient is φ = 91067500.

The previous prime is 91431979. The next prime is 91432027. The reversal of 91432021 is 12023419.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-91432021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 91431983 and 91432001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91432027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 181885 + ... + 182386.

It is an arithmetic number, because the mean of its divisors is an integer number (22949136).

Almost surely, 2^91432021 is an apocalyptic number.

It is an amenable number.

91432021 is a deficient number, since it is larger than the sum of its proper divisors (364523).

91432021 is a wasteful number, since it uses less digits than its factorization.

91432021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 364522.

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

The square root of 91432021 is about 9562.0092553814. The cubic root of 91432021 is about 450.5048178369.

The spelling of 91432021 in words is "ninety-one million, four hundred thirty-two thousand, twenty-one".