21667222 has 4 divisors (see below), whose sum is σ = 32500836. Its totient is φ = 10833610.

The previous prime is 21667211. The next prime is 21667223. The reversal of 21667222 is 22276612.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21667223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5416804 + ... + 5416807.

It is an arithmetic number, because the mean of its divisors is an integer number (8125209).

Almost surely, 2^21667222 is an apocalyptic number.

21667222 is a deficient number, since it is larger than the sum of its proper divisors (10833614).

21667222 is a wasteful number, since it uses less digits than its factorization.

21667222 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10833613.

The product of its digits is 4032, while the sum is 28.

The square root of 21667222 is about 4654.8063332431. The cubic root of 21667222 is about 278.7839353538.

The spelling of 21667222 in words is "twenty-one million, six hundred sixty-seven thousand, two hundred twenty-two".