91997120 has 28 divisors (see below), whose sum is σ = 219068904. Its totient is φ = 36798720.

The previous prime is 91997111. The next prime is 91997131. The reversal of 91997120 is 2179919.

It is a hoax number, since the sum of its digits (38) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 143426 + ... + 144065.

Almost surely, 2^91997120 is an apocalyptic number.

It is an amenable number.

91997120 is an abundant number, since it is smaller than the sum of its proper divisors (127071784).

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

91997120 is a wasteful number, since it uses less digits than its factorization.

91997120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 287508 (or 287498 counting only the distinct ones).

The product of its (nonzero) digits is 10206, while the sum is 38.

The square root of 91997120 is about 9591.5129150724. The cubic root of 91997120 is about 451.4310328644.

The spelling of 91997120 in words is "ninety-one million, nine hundred ninety-seven thousand, one hundred twenty".