221345604 has 18 divisors (see below), whose sum is σ = 559512590. Its totient is φ = 73781856.

The previous prime is 221345599. The next prime is 221345647. The reversal of 221345604 is 406543122.

221345604 is a `hidden beast` number, since 2 + 2 + 13 + 45 + 604 = 666.

221345604 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 195944004 + 25401600 = 13998^2 + 5040^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3074209 + ... + 3074280.

Almost surely, 2^221345604 is an apocalyptic number.

It is an amenable number.

221345604 is an abundant number, since it is smaller than the sum of its proper divisors (338166986).

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

221345604 is a wasteful number, since it uses less digits than its factorization.

221345604 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6148499 (or 6148494 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 27.

The square root of 221345604 is about 14877.6881268563. The cubic root of 221345604 is about 604.9093541766.

Adding to 221345604 its reverse (406543122), we get a palindrome (627888726).

The spelling of 221345604 in words is "two hundred twenty-one million, three hundred forty-five thousand, six hundred four".