21222367666 has 8 divisors (see below), whose sum is σ = 31838197104. Its totient is φ = 10609635300.

The previous prime is 21222367657. The next prime is 21222367679. The reversal of 21222367666 is 66676322212.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 757060 + ... + 784591.

It is an arithmetic number, because the mean of its divisors is an integer number (3979774638).

Almost surely, 2^21222367666 is an apocalyptic number.

21222367666 is a deficient number, since it is larger than the sum of its proper divisors (10615829438).

21222367666 is a wasteful number, since it uses less digits than its factorization.

21222367666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1548536.

The product of its digits is 435456, while the sum is 43.

Adding to 21222367666 its reverse (66676322212), we get a palindrome (87898689878).

The spelling of 21222367666 in words is "twenty-one billion, two hundred twenty-two million, three hundred sixty-seven thousand, six hundred sixty-six".