91243613 has 4 divisors (see below), whose sum is σ = 91295808. Its totient is φ = 91191420.

The previous prime is 91243609. The next prime is 91243627. The reversal of 91243613 is 31634219.

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: 31634219 = 1949 ⋅16231.

It is a cyclic number.

It is not a de Polignac number, because 91243613 - 2² = 91243609 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 (91243673) 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, 23381 + ... + 27002.

It is an arithmetic number, because the mean of its divisors is an integer number (22823952).

Almost surely, 2^91243613 is an apocalyptic number.

It is an amenable number.

91243613 is a deficient number, since it is larger than the sum of its proper divisors (52195).

91243613 is a wasteful number, since it uses less digits than its factorization.

91243613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52194.

The product of its digits is 3888, while the sum is 29.

The square root of 91243613 is about 9552.1522705619. The cubic root of 91243613 is about 450.1951630830.

The spelling of 91243613 in words is "ninety-one million, two hundred forty-three thousand, six hundred thirteen".