91890870 has 32 divisors (see below), whose sum is σ = 224703072. Its totient is φ = 24041472.

The previous prime is 91890857. The next prime is 91890889. The reversal of 91890870 is 7809819.

It is a congruent number.

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, 27307 + ... + 30486.

It is an arithmetic number, because the mean of its divisors is an integer number (7021971).

Almost surely, 2^91890870 is an apocalyptic number.

91890870 is an abundant number, since it is smaller than the sum of its proper divisors (132812202).

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

91890870 is a wasteful number, since it uses less digits than its factorization.

91890870 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57856.

The product of its (nonzero) digits is 36288, while the sum is 42.

The square root of 91890870 is about 9585.9725641168. The cubic root of 91890870 is about 451.2571758846.

The spelling of 91890870 in words is "ninety-one million, eight hundred ninety thousand, eight hundred seventy".