21657622 has 16 divisors (see below), whose sum is σ = 37255680. Its totient is φ = 9249768.

The previous prime is 21657611. The next prime is 21657631. The reversal of 21657622 is 22675612.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1779 + ... + 6817.

It is an arithmetic number, because the mean of its divisors is an integer number (2328480).

Almost surely, 2^21657622 is an apocalyptic number.

21657622 is a deficient number, since it is larger than the sum of its proper divisors (15598058).

21657622 is a wasteful number, since it uses less digits than its factorization.

21657622 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5355.

The product of its digits is 10080, while the sum is 31.

The square root of 21657622 is about 4653.7750267928. The cubic root of 21657622 is about 278.7427560841.

The spelling of 21657622 in words is "twenty-one million, six hundred fifty-seven thousand, six hundred twenty-two".