221255656 has 8 divisors (see below), whose sum is σ = 414854370. Its totient is φ = 110627824.

The previous prime is 221255651. The next prime is 221255677. The reversal of 221255656 is 656552122.

It can be written as a sum of positive squares in only one way, i.e., 120253156 + 101002500 = 10966^2 + 10050^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (221255651) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13828471 + ... + 13828486.

Almost surely, 2^221255656 is an apocalyptic number.

It is an amenable number.

221255656 is a deficient number, since it is larger than the sum of its proper divisors (193598714).

221255656 is a wasteful number, since it uses less digits than its factorization.

221255656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27656963 (or 27656959 counting only the distinct ones).

The product of its digits is 36000, while the sum is 34.

The square root of 221255656 is about 14874.6649037886. The cubic root of 221255656 is about 604.8274042644.

The spelling of 221255656 in words is "two hundred twenty-one million, two hundred fifty-five thousand, six hundred fifty-six".