221768144 has 40 divisors (see below), whose sum is σ = 463715112. Its totient is φ = 102136320.

The previous prime is 221768143. The next prime is 221768149. The reversal of 221768144 is 441867122.

It can be written as a sum of positive squares in 4 ways, for example, as 36481600 + 185286544 = 6040^2 + 13612^2 .

It is a super-2 number, since 2×221768144² = 98362219386409472, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221768143) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 136682 + ... + 138294.

Almost surely, 2^221768144 is an apocalyptic number.

It is an amenable number.

221768144 is an abundant number, since it is smaller than the sum of its proper divisors (241946968).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

221768144 is a wasteful number, since it uses less digits than its factorization.

221768144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2295 (or 2289 counting only the distinct ones).

The product of its digits is 21504, while the sum is 35.

The square root of 221768144 is about 14891.8818152710. The cubic root of 221768144 is about 605.2940255138.

The spelling of 221768144 in words is "two hundred twenty-one million, seven hundred sixty-eight thousand, one hundred forty-four".