221531330 has 16 divisors (see below), whose sum is σ = 400962744. Its totient is φ = 88122240.

The previous prime is 221531309. The next prime is 221531341. The reversal of 221531330 is 33135122.

It can be written as a sum of positive squares in 4 ways, for example, as 96963409 + 124567921 = 9847^2 + 11161^2 .

It is a super-2 number, since 2×221531330² = 98152260343137800, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 59387 + ... + 63006.

Almost surely, 2^221531330 is an apocalyptic number.

221531330 is a deficient number, since it is larger than the sum of its proper divisors (179431414).

221531330 is a wasteful number, since it uses less digits than its factorization.

221531330 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122581.

The product of its (nonzero) digits is 540, while the sum is 20.

The square root of 221531330 is about 14883.9285808553. The cubic root of 221531330 is about 605.0784953818.

Adding to 221531330 its reverse (33135122), we get a palindrome (254666452).

The spelling of 221531330 in words is "two hundred twenty-one million, five hundred thirty-one thousand, three hundred thirty".