21707222 has 4 divisors (see below), whose sum is σ = 32560836. Its totient is φ = 10853610.

The previous prime is 21707219. The next prime is 21707227. The reversal of 21707222 is 22270712.

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 (21707227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5426804 + ... + 5426807.

It is an arithmetic number, because the mean of its divisors is an integer number (8140209).

Almost surely, 2^21707222 is an apocalyptic number.

21707222 is a deficient number, since it is larger than the sum of its proper divisors (10853614).

21707222 is a wasteful number, since it uses less digits than its factorization.

21707222 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10853613.

The product of its (nonzero) digits is 784, while the sum is 23.

The square root of 21707222 is about 4659.1009862419. The cubic root of 21707222 is about 278.9553848402.

Adding to 21707222 its reverse (22270712), we get a palindrome (43977934).

The spelling of 21707222 in words is "twenty-one million, seven hundred seven thousand, two hundred twenty-two".