222521666 has 32 divisors (see below), whose sum is σ = 348850800. Its totient is φ = 106389504.

The previous prime is 222521657. The next prime is 222521671. The reversal of 222521666 is 666125222.

It can be written as a sum of positive squares in 8 ways, for example, as 66896041 + 155625625 = 8179^2 + 12475^2 .

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, 1152866 + ... + 1153058.

Almost surely, 2^222521666 is an apocalyptic number.

222521666 is a deficient number, since it is larger than the sum of its proper divisors (126329134).

222521666 is a wasteful number, since it uses less digits than its factorization.

222521666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 470.

The product of its digits is 17280, while the sum is 32.

The square root of 222521666 is about 14917.1601184676. The cubic root of 222521666 is about 605.9788048950.

Adding to 222521666 its reverse (666125222), we get a palindrome (888646888).

The spelling of 222521666 in words is "two hundred twenty-two million, five hundred twenty-one thousand, six hundred sixty-six".