2221904 has 10 divisors (see below), whose sum is σ = 4304970. Its totient is φ = 1110944.

The previous prime is 2221889. The next prime is 2221907. The reversal of 2221904 is 4091222.

It can be written as a sum of positive squares in only one way, i.e., 1123600 + 1098304 = 1060^2 + 1048^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2221907) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69419 + ... + 69450.

It is an arithmetic number, because the mean of its divisors is an integer number (430497).

2^2221904 is an apocalyptic number.

It is an amenable number.

2221904 is a deficient number, since it is larger than the sum of its proper divisors (2083066).

2221904 is a wasteful number, since it uses less digits than its factorization.

2221904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138877 (or 138871 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 2221904 is about 1490.6052462003. The cubic root of 2221904 is about 130.4893587522.

It can be divided in two parts, 2221 and 904, that added together give a 5-th power (3125 = 5⁵).

The spelling of 2221904 in words is "two million, two hundred twenty-one thousand, nine hundred four".