91073753021 has 4 divisors (see below), whose sum is σ = 91088638044. Its totient is φ = 91058868000.

The previous prime is 91073752997. The next prime is 91073753053. The reversal of 91073753021 is 12035737019.

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 33219072121 + 57854680900 = 182261^2 + 240530^2 .

It is a cyclic number.

It is not a de Polignac number, because 91073753021 - 2¹⁸ = 91073490877 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 (91073713021) 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, 7433330 + ... + 7445571.

It is an arithmetic number, because the mean of its divisors is an integer number (22772159511).

Almost surely, 2^91073753021 is an apocalyptic number.

It is an amenable number.

91073753021 is a deficient number, since it is larger than the sum of its proper divisors (14885023).

91073753021 is a wasteful number, since it uses less digits than its factorization.

91073753021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14885022.

The product of its (nonzero) digits is 39690, while the sum is 38.

The spelling of 91073753021 in words is "ninety-one billion, seventy-three million, seven hundred fifty-three thousand, twenty-one".