91613231 has 4 divisors (see below), whose sum is σ = 96435000. Its totient is φ = 86791464.

The previous prime is 91613227. The next prime is 91613237. The reversal of 91613231 is 13231619.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 91613231 - 2² = 91613227 is a prime.

It is a super-2 number, since 2×91613231² = 16785968188518722, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 91613231.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91613237) 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, 2410856 + ... + 2410893.

It is an arithmetic number, because the mean of its divisors is an integer number (24108750).

Almost surely, 2^91613231 is an apocalyptic number.

91613231 is a deficient number, since it is larger than the sum of its proper divisors (4821769).

91613231 is a wasteful number, since it uses less digits than its factorization.

91613231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4821768.

The product of its digits is 972, while the sum is 26.

The square root of 91613231 is about 9571.4800840831. The cubic root of 91613231 is about 450.8022413754.

The spelling of 91613231 in words is "ninety-one million, six hundred thirteen thousand, two hundred thirty-one".