90991885 has 8 divisors (see below), whose sum is σ = 109241856. Its totient is φ = 72759120.

The previous prime is 90991883. The next prime is 90991889. The reversal of 90991885 is 58819909.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 90991885 - 2¹ = 90991883 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90991883) 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, 16420 + ... + 21250.

It is an arithmetic number, because the mean of its divisors is an integer number (13655232).

Almost surely, 2^90991885 is an apocalyptic number.

It is an amenable number.

90991885 is a deficient number, since it is larger than the sum of its proper divisors (18249971).

90991885 is a wasteful number, since it uses less digits than its factorization.

90991885 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8603.

The product of its (nonzero) digits is 233280, while the sum is 49.

The square root of 90991885 is about 9538.9666631140. The cubic root of 90991885 is about 449.7807738756.

The spelling of 90991885 in words is "ninety million, nine hundred ninety-one thousand, eight hundred eighty-five".