21838456 has 24 divisors (see below), whose sum is σ = 41992560. Its totient is φ = 10642560.

The previous prime is 21838451. The next prime is 21838457. The reversal of 21838456 is 65483812.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21838451) 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 in 5 ways as a sum of consecutive naturals, for example, 90496 + ... + 90736.

It is an arithmetic number, because the mean of its divisors is an integer number (1749690).

Almost surely, 2^21838456 is an apocalyptic number.

It is an amenable number.

21838456 is a deficient number, since it is larger than the sum of its proper divisors (20154104).

21838456 is an equidigital number, since it uses as much as digits as its factorization.

21838456 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 535 (or 290 counting only the distinct ones).

The product of its digits is 46080, while the sum is 37.

The square root of 21838456 is about 4673.1633825493. The cubic root of 21838456 is about 279.5164101676.

The spelling of 21838456 in words is "twenty-one million, eight hundred thirty-eight thousand, four hundred fifty-six".