221400556 has 24 divisors (see below), whose sum is σ = 419683824. Its totient is φ = 101590080.

The previous prime is 221400527. The next prime is 221400601. The reversal of 221400556 is 655004122.

It is a self number, because there is not a number n which added to its sum of digits gives 221400556.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3310 + ... + 21301.

It is an arithmetic number, because the mean of its divisors is an integer number (17486826).

Almost surely, 2^221400556 is an apocalyptic number.

221400556 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

221400556 is a deficient number, since it is larger than the sum of its proper divisors (198283268).

221400556 is a wasteful number, since it uses less digits than its factorization.

221400556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24801 (or 24799 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 25.

The square root of 221400556 is about 14879.5348045562. The cubic root of 221400556 is about 604.9594089744.

Adding to 221400556 its reverse (655004122), we get a palindrome (876404678).

The spelling of 221400556 in words is "two hundred twenty-one million, four hundred thousand, five hundred fifty-six".