91321013 has 4 divisors (see below), whose sum is σ = 104366880. Its totient is φ = 78275148.

The previous prime is 91321007. The next prime is 91321019. The reversal of 91321013 is 31012319.

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 an interprime number because it is at equal distance from previous prime (91321007) and next prime (91321019).

It is not a de Polignac number, because 91321013 - 2⁴ = 91320997 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 (91321019) 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, 6522923 + ... + 6522936.

It is an arithmetic number, because the mean of its divisors is an integer number (26091720).

Almost surely, 2^91321013 is an apocalyptic number.

It is an amenable number.

91321013 is a deficient number, since it is larger than the sum of its proper divisors (13045867).

91321013 is a wasteful number, since it uses less digits than its factorization.

91321013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13045866.

The product of its (nonzero) digits is 162, while the sum is 20.

The square root of 91321013 is about 9556.2028546908. The cubic root of 91321013 is about 450.3224240727.

The spelling of 91321013 in words is "ninety-one million, three hundred twenty-one thousand, thirteen".