221871904 has 24 divisors (see below), whose sum is σ = 437851008. Its totient is φ = 110671680.

The previous prime is 221871901. The next prime is 221871931. The reversal of 221871904 is 409178122.

It is a self number, because there is not a number n which added to its sum of digits gives 221871904.

It is not an unprimeable number, because it can be changed into a prime (221871901) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5749 + ... + 21835.

It is an arithmetic number, because the mean of its divisors is an integer number (18243792).

Almost surely, 2^221871904 is an apocalyptic number.

It is an amenable number.

221871904 is a deficient number, since it is larger than the sum of its proper divisors (215979104).

221871904 is a wasteful number, since it uses less digits than its factorization.

221871904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16528 (or 16520 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 34.

The square root of 221871904 is about 14895.3651851843. The cubic root of 221871904 is about 605.3884116513.

The spelling of 221871904 in words is "two hundred twenty-one million, eight hundred seventy-one thousand, nine hundred four".