221404556 has 6 divisors (see below), whose sum is σ = 387457980. Its totient is φ = 110702276.

The previous prime is 221404523. The next prime is 221404567. The reversal of 221404556 is 655404122.

221404556 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27675566 + ... + 27675573.

It is an arithmetic number, because the mean of its divisors is an integer number (64576330).

Almost surely, 2^221404556 is an apocalyptic number.

It is an amenable number.

221404556 is a deficient number, since it is larger than the sum of its proper divisors (166053424).

221404556 is a wasteful number, since it uses less digits than its factorization.

221404556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55351143 (or 55351141 counting only the distinct ones).

The product of its (nonzero) digits is 9600, while the sum is 29.

The square root of 221404556 is about 14879.6692167534. The cubic root of 221404556 is about 604.9630521798.

Adding to 221404556 its reverse (655404122), we get a palindrome (876808678).

The spelling of 221404556 in words is "two hundred twenty-one million, four hundred four thousand, five hundred fifty-six".