21522238 has 16 divisors (see below), whose sum is σ = 34389360. Its totient is φ = 10066816.

The previous prime is 21522223. The next prime is 21522251. The reversal of 21522238 is 83222512.

It is a congruent number.

It is an unprimeable number.

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 in 7 ways as a sum of consecutive naturals, for example, 4053 + ... + 7711.

It is an arithmetic number, because the mean of its divisors is an integer number (2149335).

Almost surely, 2^21522238 is an apocalyptic number.

21522238 is a deficient number, since it is larger than the sum of its proper divisors (12867122).

21522238 is a wasteful number, since it uses less digits than its factorization.

21522238 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3851.

The product of its digits is 1920, while the sum is 25.

The square root of 21522238 is about 4639.2066132045. The cubic root of 21522238 is about 278.1607251672.

The spelling of 21522238 in words is "twenty-one million, five hundred twenty-two thousand, two hundred thirty-eight".