21814720 has 28 divisors (see below), whose sum is σ = 51947064. Its totient is φ = 8725760.

The previous prime is 21814711. The next prime is 21814733. The reversal of 21814720 is 2741812.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 33766 + ... + 34405.

Almost surely, 2^21814720 is an apocalyptic number.

21814720 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21814720 is an abundant number, since it is smaller than the sum of its proper divisors (30132344).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21814720 is an equidigital number, since it uses as much as digits as its factorization.

21814720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68188 (or 68178 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 25.

The square root of 21814720 is about 4670.6230847715. The cubic root of 21814720 is about 279.4151055904.

The spelling of 21814720 in words is "twenty-one million, eight hundred fourteen thousand, seven hundred twenty".