91981233 has 12 divisors (see below), whose sum is σ = 134355780. Its totient is φ = 60631296.

The previous prime is 91981231. The next prime is 91981249. The reversal of 91981233 is 33218919.

It can be written as a sum of positive squares in 2 ways, for example, as 5992704 + 85988529 = 2448^2 + 9273^2 .

It is not a de Polignac number, because 91981233 - 2¹ = 91981231 is a prime.

It is not an unprimeable number, because it can be changed into a prime (91981231) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 56616 + ... + 58217.

It is an arithmetic number, because the mean of its divisors is an integer number (11196315).

Almost surely, 2^91981233 is an apocalyptic number.

It is an amenable number.

91981233 is a deficient number, since it is larger than the sum of its proper divisors (42374547).

91981233 is a wasteful number, since it uses less digits than its factorization.

91981233 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114928 (or 114925 counting only the distinct ones).

The product of its digits is 11664, while the sum is 36.

The square root of 91981233 is about 9590.6846992277. The cubic root of 91981233 is about 451.4050454650.

The spelling of 91981233 in words is "ninety-one million, nine hundred eighty-one thousand, two hundred thirty-three".