91983890 has 16 divisors (see below), whose sum is σ = 166099032. Its totient is φ = 36676224.

The previous prime is 91983863. The next prime is 91983893. The reversal of 91983890 is 9838919.

It can be written as a sum of positive squares in 4 ways, for example, as 34845409 + 57138481 = 5903^2 + 7559^2 .

It is a super-2 number, since 2×91983890² = 16922072039064200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (91983893) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11339 + ... + 17678.

Almost surely, 2^91983890 is an apocalyptic number.

91983890 is a deficient number, since it is larger than the sum of its proper divisors (74115142).

91983890 is a wasteful number, since it uses less digits than its factorization.

91983890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29341.

The product of its (nonzero) digits is 139968, while the sum is 47.

The square root of 91983890 is about 9590.8232180559. The cubic root of 91983890 is about 451.4093919011.

The spelling of 91983890 in words is "ninety-one million, nine hundred eighty-three thousand, eight hundred ninety".