221257636 has 12 divisors (see below), whose sum is σ = 387344860. Its totient is φ = 110587680.

The previous prime is 221257583. The next prime is 221257637. The reversal of 221257636 is 636752122.

It can be written as a sum of positive squares in 2 ways, for example, as 70459236 + 150798400 = 8394^2 + 12280^2 .

It is not an unprimeable number, because it can be changed into a prime (221257637) 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 in 3 ways as a sum of consecutive naturals, for example, 4030 + ... + 21418.

Almost surely, 2^221257636 is an apocalyptic number.

It is an amenable number.

221257636 is a deficient number, since it is larger than the sum of its proper divisors (166087224).

221257636 is a wasteful number, since it uses less digits than its factorization.

221257636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20574 (or 20572 counting only the distinct ones).

The product of its digits is 30240, while the sum is 34.

The square root of 221257636 is about 14874.7314597609. The cubic root of 221257636 is about 604.8292084438.

The spelling of 221257636 in words is "two hundred twenty-one million, two hundred fifty-seven thousand, six hundred thirty-six".