91993890 has 32 divisors (see below), whose sum is σ = 221846976. Its totient is φ = 24413760.

The previous prime is 91993883. The next prime is 91993901. The reversal of 91993890 is 9839919.

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, 937 + ... + 13596.

It is an arithmetic number, because the mean of its divisors is an integer number (6932718).

Almost surely, 2^91993890 is an apocalyptic number.

91993890 is an abundant number, since it is smaller than the sum of its proper divisors (129853086).

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

91993890 is a wasteful number, since it uses less digits than its factorization.

91993890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14754.

The product of its (nonzero) digits is 157464, while the sum is 48.

The square root of 91993890 is about 9591.3445355696. The cubic root of 91993890 is about 451.4257495856.

The spelling of 91993890 in words is "ninety-one million, nine hundred ninety-three thousand, eight hundred ninety".