91456021 has 4 divisors (see below), whose sum is σ = 91662912. Its totient is φ = 91249132.

The previous prime is 91455967. The next prime is 91456061. The reversal of 91456021 is 12065419.

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 not a de Polignac number, because 91456021 - 2¹⁵ = 91423253 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91456061) 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, 102781 + ... + 103666.

It is an arithmetic number, because the mean of its divisors is an integer number (22915728).

Almost surely, 2^91456021 is an apocalyptic number.

It is an amenable number.

91456021 is a deficient number, since it is larger than the sum of its proper divisors (206891).

91456021 is a wasteful number, since it uses less digits than its factorization.

91456021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 206890.

The product of its (nonzero) digits is 2160, while the sum is 28.

The square root of 91456021 is about 9563.2641394034. The cubic root of 91456021 is about 450.5442320729.

The spelling of 91456021 in words is "ninety-one million, four hundred fifty-six thousand, twenty-one".