221630666 has 32 divisors (see below), whose sum is σ = 370418832. Its totient is φ = 98979840.

The previous prime is 221630659. The next prime is 221630671. The reversal of 221630666 is 666036122.

221630666 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 8 ways, for example, as 135233641 + 86397025 = 11629^2 + 9295^2 .

It is a super-2 number, since 2×221630666² = 98240304223207112, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 49430 + ... + 53726.

Almost surely, 2^221630666 is an apocalyptic number.

221630666 is a deficient number, since it is larger than the sum of its proper divisors (148788166).

221630666 is a wasteful number, since it uses less digits than its factorization.

221630666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4394.

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

The square root of 221630666 is about 14887.2652290473. The cubic root of 221630666 is about 605.1689221635.

Adding to 221630666 its reverse (666036122), we get a palindrome (887666788).

The spelling of 221630666 in words is "two hundred twenty-one million, six hundred thirty thousand, six hundred sixty-six".