21408622 has 16 divisors (see below), whose sum is σ = 32811120. Its totient is φ = 10473408.

The previous prime is 21408613. The next prime is 21408623. The reversal of 21408622 is 22680412.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21408623) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 46618 + ... + 47074.

It is an arithmetic number, because the mean of its divisors is an integer number (2050695).

Almost surely, 2^21408622 is an apocalyptic number.

21408622 is a deficient number, since it is larger than the sum of its proper divisors (11402498).

21408622 is a wasteful number, since it uses less digits than its factorization.

21408622 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 915.

The product of its (nonzero) digits is 1536, while the sum is 25.

The square root of 21408622 is about 4626.9452125566. The cubic root of 21408622 is about 277.6703907154.

The spelling of 21408622 in words is "twenty-one million, four hundred eight thousand, six hundred twenty-two".