221553990 has 96 divisors (see below), whose sum is σ = 671860800. Its totient is φ = 50633856.

The previous prime is 221553989. The next prime is 221554031. The reversal of 221553990 is 99355122.

It is a happy number.

221553990 is a `hidden beast` number, since 22 + 15 + 539 + 90 = 666.

It is a congruent number.

It is an unprimeable number.

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 47 ways as a sum of consecutive naturals, for example, 27282 + ... + 34458.

It is an arithmetic number, because the mean of its divisors is an integer number (6998550).

Almost surely, 2^221553990 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221553990, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (335930400).

221553990 is an abundant number, since it is smaller than the sum of its proper divisors (450306810).

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

221553990 is a wasteful number, since it uses less digits than its factorization.

221553990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7211 (or 7194 counting only the distinct ones).

The product of its (nonzero) digits is 24300, while the sum is 36.

The square root of 221553990 is about 14884.6897851450. The cubic root of 221553990 is about 605.0991254378.

The spelling of 221553990 in words is "two hundred twenty-one million, five hundred fifty-three thousand, nine hundred ninety".