221220090 has 96 divisors (see below), whose sum is σ = 707930496. Its totient is φ = 46673280.

The previous prime is 221220089. The next prime is 221220101. The reversal of 221220090 is 90022122.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

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 47 ways as a sum of consecutive naturals, for example, 5316 + ... + 21695.

It is an arithmetic number, because the mean of its divisors is an integer number (7374276).

Almost surely, 2^221220090 is an apocalyptic number.

221220090 is an abundant number, since it is smaller than the sum of its proper divisors (486710406).

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

221220090 is a wasteful number, since it uses less digits than its factorization.

221220090 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27044 (or 27041 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 221220090 is about 14873.4693330104. The cubic root of 221220090 is about 604.7949946308.

The spelling of 221220090 in words is "two hundred twenty-one million, two hundred twenty thousand, ninety".