91671720 has 64 divisors (see below), whose sum is σ = 314305920. Its totient is φ = 20953344.

The previous prime is 91671707. The next prime is 91671731. The reversal of 91671720 is 2717619.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 53727 + ... + 55406.

It is an arithmetic number, because the mean of its divisors is an integer number (4911030).

Almost surely, 2^91671720 is an apocalyptic number.

It is an amenable number.

91671720 is an abundant number, since it is smaller than the sum of its proper divisors (222634200).

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

91671720 is a wasteful number, since it uses less digits than its factorization.

91671720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109154 (or 109150 counting only the distinct ones).

The product of its (nonzero) digits is 5292, while the sum is 33.

The square root of 91671720 is about 9574.5349756529. The cubic root of 91671720 is about 450.8981567899.

The spelling of 91671720 in words is "ninety-one million, six hundred seventy-one thousand, seven hundred twenty".