221656616 has 16 divisors (see below), whose sum is σ = 421300500. Its totient is φ = 109309824.

The previous prime is 221656609. The next prime is 221656621. The reversal of 221656616 is 616656122.

It can be written as a sum of positive squares in 2 ways, for example, as 214739716 + 6916900 = 14654^2 + 2630^2 .

It is an unprimeable number.

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 in 3 ways as a sum of consecutive naturals, for example, 189191 + ... + 190358.

Almost surely, 2^221656616 is an apocalyptic number.

It is an amenable number.

221656616 is a deficient number, since it is larger than the sum of its proper divisors (199643884).

221656616 is a wasteful number, since it uses less digits than its factorization.

221656616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 379628 (or 379624 counting only the distinct ones).

The product of its digits is 25920, while the sum is 35.

The square root of 221656616 is about 14888.1367538050. The cubic root of 221656616 is about 605.1925403161.

The spelling of 221656616 in words is "two hundred twenty-one million, six hundred fifty-six thousand, six hundred sixteen".