90991212 has 48 divisors (see below), whose sum is σ = 236540640. Its totient is φ = 27030528.

The previous prime is 90991193. The next prime is 90991213. The reversal of 90991212 is 21219909.

It is a super-2 number, since 2×90991212² = 16558801322457888, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (90991213) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5533 + ... + 14580.

It is an arithmetic number, because the mean of its divisors is an integer number (4927930).

Almost surely, 2^90991212 is an apocalyptic number.

It is an amenable number.

90991212 is an abundant number, since it is smaller than the sum of its proper divisors (145549428).

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

90991212 is a wasteful number, since it uses less digits than its factorization.

90991212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20162 (or 20160 counting only the distinct ones).

The product of its (nonzero) digits is 2916, while the sum is 33.

The square root of 90991212 is about 9538.9313866911. The cubic root of 90991212 is about 449.7796649737.

The spelling of 90991212 in words is "ninety million, nine hundred ninety-one thousand, two hundred twelve".