91811904 has 56 divisors (see below), whose sum is σ = 246034560. Its totient is φ = 30211584.

The previous prime is 91811903. The next prime is 91811939. The reversal of 91811904 is 40911819.

It is a super-2 number, since 2×91811904² = 16858851432210432, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (91811903) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12142 + ... + 18194.

Almost surely, 2^91811904 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 91811904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (123017280).

91811904 is an abundant number, since it is smaller than the sum of its proper divisors (154222656).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

91811904 is a wasteful number, since it uses less digits than its factorization.

91811904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6147 (or 6137 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 33.

The square root of 91811904 is about 9581.8528479621. The cubic root of 91811904 is about 451.1278769081.

The spelling of 91811904 in words is "ninety-one million, eight hundred eleven thousand, nine hundred four".