91999944 has 48 divisors (see below), whose sum is σ = 253878300. Its totient is φ = 30086784.

The previous prime is 91999907. The next prime is 91999951. The reversal of 91999944 is 44999919.

It can be written as a sum of positive squares in 2 ways, for example, as 89075844 + 2924100 = 9438^2 + 1710^2 .

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8239 + ... + 15870.

Almost surely, 2^91999944 is an apocalyptic number.

It is an amenable number.

91999944 is an abundant number, since it is smaller than the sum of its proper divisors (161878356).

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

91999944 is a wasteful number, since it uses less digits than its factorization.

91999944 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24174 (or 24167 counting only the distinct ones).

The product of its digits is 944784, while the sum is 54.

The square root of 91999944 is about 9591.6601274232. The cubic root of 91999944 is about 451.4356519517.

The spelling of 91999944 in words is "ninety-one million, nine hundred ninety-nine thousand, nine hundred forty-four".