90909918 has 64 divisors (see below), whose sum is σ = 227543040. Its totient is φ = 26654400.

The previous prime is 90909901. The next prime is 90909919. The reversal of 90909918 is 81990909.

It is a super-2 number, since 2×90909918² = 16529226381533448, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90909919) 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, 15946 + ... + 20882.

It is an arithmetic number, because the mean of its divisors is an integer number (3555360).

Almost surely, 2^90909918 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 90909918, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (113771520).

90909918 is an abundant number, since it is smaller than the sum of its proper divisors (136633122).

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

90909918 is a wasteful number, since it uses less digits than its factorization.

90909918 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4990 (or 4984 counting only the distinct ones).

The product of its (nonzero) digits is 52488, while the sum is 45.

The square root of 90909918 is about 9534.6692653705. The cubic root of 90909918 is about 449.6456766398.

The spelling of 90909918 in words is "ninety million, nine hundred nine thousand, nine hundred eighteen".