91869890 has 64 divisors (see below), whose sum is σ = 196992000. Its totient is φ = 30191616.

The previous prime is 91869881. The next prime is 91869893. The reversal of 91869890 is 9896819.

It is a super-2 number, since 2×91869890² = 16880153377224200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (91869893) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 204386 + ... + 204834.

It is an arithmetic number, because the mean of its divisors is an integer number (3078000).

Almost surely, 2^91869890 is an apocalyptic number.

91869890 is an abundant number, since it is smaller than the sum of its proper divisors (105122110).

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

91869890 is a wasteful number, since it uses less digits than its factorization.

91869890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 579.

The product of its (nonzero) digits is 279936, while the sum is 50.

The square root of 91869890 is about 9584.8781943226. The cubic root of 91869890 is about 451.2228304480. Note that the first 3 decimals are identical.

The spelling of 91869890 in words is "ninety-one million, eight hundred sixty-nine thousand, eight hundred ninety".