90991056 has 40 divisors (see below), whose sum is σ = 253143520. Its totient is φ = 27997056.

The previous prime is 90991051. The next prime is 90991073. The reversal of 90991056 is 65019909.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90991051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 72286 + ... + 73533.

It is an arithmetic number, because the mean of its divisors is an integer number (6328588).

Almost surely, 2^90991056 is an apocalyptic number.

It is an amenable number.

90991056 is an abundant number, since it is smaller than the sum of its proper divisors (162152464).

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

90991056 is a wasteful number, since it uses less digits than its factorization.

90991056 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 145843 (or 145837 counting only the distinct ones).

The product of its (nonzero) digits is 21870, while the sum is 39.

The square root of 90991056 is about 9538.9232096710. The cubic root of 90991056 is about 449.7794079318.

The spelling of 90991056 in words is "ninety million, nine hundred ninety-one thousand, fifty-six".