221351990 has 16 divisors (see below), whose sum is σ = 398709648. Its totient is φ = 88479456.

The previous prime is 221351969. The next prime is 221352007. The reversal of 221351990 is 99153122.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9269 + ... + 22991.

It is an arithmetic number, because the mean of its divisors is an integer number (24919353).

Almost surely, 2^221351990 is an apocalyptic number.

221351990 is a deficient number, since it is larger than the sum of its proper divisors (177357658).

221351990 is a wasteful number, since it uses less digits than its factorization.

221351990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15343.

The product of its (nonzero) digits is 4860, while the sum is 32.

The square root of 221351990 is about 14877.9027419862. The cubic root of 221351990 is about 604.9151714957.

The spelling of 221351990 in words is "two hundred twenty-one million, three hundred fifty-one thousand, nine hundred ninety".