221604012 has 120 divisors (see below), whose sum is σ = 666758400. Its totient is φ = 62868960.

The previous prime is 221604007. The next prime is 221604029. The reversal of 221604012 is 210406122.

221604012 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×221604012² = 98216676268992288, which contains 22 as substring.

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

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 451087 + ... + 451577.

It is an arithmetic number, because the mean of its divisors is an integer number (5556320).

Almost surely, 2^221604012 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221604012, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (333379200).

221604012 is an abundant number, since it is smaller than the sum of its proper divisors (445154388).

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

221604012 is a wasteful number, since it uses less digits than its factorization.

221604012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 713 (or 702 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 221604012 is about 14886.3700074934. The cubic root of 221604012 is about 605.1446613525.

The spelling of 221604012 in words is "two hundred twenty-one million, six hundred four thousand, twelve".