91155920 has 40 divisors (see below), whose sum is σ = 223095840. Its totient is φ = 34542720.

The previous prime is 91155917. The next prime is 91155931. The reversal of 91155920 is 2955119.

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28466 + ... + 31505.

It is an arithmetic number, because the mean of its divisors is an integer number (5577396).

Almost surely, 2^91155920 is an apocalyptic number.

It is an amenable number.

91155920 is an abundant number, since it is smaller than the sum of its proper divisors (131939920).

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

91155920 is a wasteful number, since it uses less digits than its factorization.

91155920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60003 (or 59997 counting only the distinct ones).

The product of its (nonzero) digits is 4050, while the sum is 32.

The square root of 91155920 is about 9547.5609450791. The cubic root of 91155920 is about 450.0508913637.

The spelling of 91155920 in words is "ninety-one million, one hundred fifty-five thousand, nine hundred twenty".