91366021 has 4 divisors (see below), whose sum is σ = 94313344. Its totient is φ = 88418700.

The previous prime is 91366001. The next prime is 91366049. The reversal of 91366021 is 12066319.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12066319 = 499 ⋅24181.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-91366021 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 (91366001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1473615 + ... + 1473676.

It is an arithmetic number, because the mean of its divisors is an integer number (23578336).

Almost surely, 2^91366021 is an apocalyptic number.

It is an amenable number.

91366021 is a deficient number, since it is larger than the sum of its proper divisors (2947323).

91366021 is a wasteful number, since it uses less digits than its factorization.

91366021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2947322.

The product of its (nonzero) digits is 1944, while the sum is 28.

The square root of 91366021 is about 9558.5574748494. The cubic root of 91366021 is about 450.3963931121.

The spelling of 91366021 in words is "ninety-one million, three hundred sixty-six thousand, twenty-one".