22121656 has 8 divisors (see below), whose sum is σ = 41478120. Its totient is φ = 11060824.

The previous prime is 22121623. The next prime is 22121663. The reversal of 22121656 is 65612122.

It is a tau number, because it is divible by the number of its divisors (8).

It is a self number, because there is not a number n which added to its sum of digits gives 22121656.

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 as a sum of consecutive naturals, namely, 1382596 + ... + 1382611.

It is an arithmetic number, because the mean of its divisors is an integer number (5184765).

Almost surely, 2^22121656 is an apocalyptic number.

It is an amenable number.

22121656 is a deficient number, since it is larger than the sum of its proper divisors (19356464).

22121656 is a wasteful number, since it uses less digits than its factorization.

22121656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2765213 (or 2765209 counting only the distinct ones).

The product of its digits is 1440, while the sum is 25.

The square root of 22121656 is about 4703.3664539349. The cubic root of 22121656 is about 280.7194762114.

Adding to 22121656 its reverse (65612122), we get a palindrome (87733778).

The spelling of 22121656 in words is "twenty-two million, one hundred twenty-one thousand, six hundred fifty-six".