221606636 has 12 divisors (see below), whose sum is σ = 388094112. Its totient is φ = 110722608.

The previous prime is 221606573. The next prime is 221606669. The reversal of 221606636 is 636606122.

It is a super-2 number, since 2×221606636² = 98219002238472992, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13775 + ... + 25158.

It is an arithmetic number, because the mean of its divisors is an integer number (32341176).

Almost surely, 2^221606636 is an apocalyptic number.

It is an amenable number.

221606636 is a deficient number, since it is larger than the sum of its proper divisors (166487476).

221606636 is a wasteful number, since it uses less digits than its factorization.

221606636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40360 (or 40358 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 32.

The square root of 221606636 is about 14886.4581415460. The cubic root of 221606636 is about 605.1470498371.

The spelling of 221606636 in words is "two hundred twenty-one million, six hundred six thousand, six hundred thirty-six".