90621855 has 64 divisors (see below), whose sum is σ = 168030720. Its totient is φ = 46303488.

The previous prime is 90621823. The next prime is 90621857. The reversal of 90621855 is 55812609.

It is a happy number.

It is not a de Polignac number, because 90621855 - 2⁵ = 90621823 is a prime.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90621857) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 388819 + ... + 389051.

It is an arithmetic number, because the mean of its divisors is an integer number (2625480).

Almost surely, 2^90621855 is an apocalyptic number.

90621855 is a deficient number, since it is larger than the sum of its proper divisors (77408865).

90621855 is a wasteful number, since it uses less digits than its factorization.

90621855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 357 (or 351 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 36.

The square root of 90621855 is about 9519.5511974042. The cubic root of 90621855 is about 449.1702487467.

The spelling of 90621855 in words is "ninety million, six hundred twenty-one thousand, eight hundred fifty-five".