221090920 has 32 divisors (see below), whose sum is σ = 499237920. Its totient is φ = 88119360.

The previous prime is 221090911. The next prime is 221090921. The reversal of 221090920 is 29090122.

It is not an unprimeable number, because it can be changed into a prime (221090921) 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, 1555 + ... + 21085.

It is an arithmetic number, because the mean of its divisors is an integer number (15601185).

Almost surely, 2^221090920 is an apocalyptic number.

221090920 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221090920 is an abundant number, since it is smaller than the sum of its proper divisors (278147000).

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

221090920 is a wasteful number, since it uses less digits than its factorization.

221090920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19825 (or 19821 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 25.

The square root of 221090920 is about 14869.1264033903. The cubic root of 221090920 is about 604.6772588210.

The spelling of 221090920 in words is "two hundred twenty-one million, ninety thousand, nine hundred twenty".