91431312 has 80 divisors (see below), whose sum is σ = 276565632. Its totient is φ = 25482240.

The previous prime is 91431293. The next prime is 91431313. The reversal of 91431312 is 21313419.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is not an unprimeable number, because it can be changed into a prime (91431313) 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 15 ways as a sum of consecutive naturals, for example, 10458 + ... + 17094.

Almost surely, 2^91431312 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 91431312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (138282816).

91431312 is an abundant number, since it is smaller than the sum of its proper divisors (185134320).

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

91431312 is a wasteful number, since it uses less digits than its factorization.

91431312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6696 (or 6690 counting only the distinct ones).

The product of its digits is 648, while the sum is 24.

The square root of 91431312 is about 9561.9721815115. The cubic root of 91431312 is about 450.5036533698.

The spelling of 91431312 in words is "ninety-one million, four hundred thirty-one thousand, three hundred twelve".