21814457 has 8 divisors (see below), whose sum is σ = 25440000. Its totient is φ = 18697812.

The previous prime is 21814447. The next prime is 21814487. The reversal of 21814457 is 75441812.

It is a happy number.

It is not a de Polignac number, because 21814457 - 2¹⁰ = 21813433 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21814447) 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, 31457 + ... + 32142.

It is an arithmetic number, because the mean of its divisors is an integer number (3180000).

Almost surely, 2^21814457 is an apocalyptic number.

It is an amenable number.

21814457 is a deficient number, since it is larger than the sum of its proper divisors (3625543).

21814457 is an frugal number, since it uses more digits than its factorization.

21814457 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63620 (or 63606 counting only the distinct ones).

The product of its digits is 8960, while the sum is 32.

The square root of 21814457 is about 4670.5949299848. The cubic root of 21814457 is about 279.4139827023.

The spelling of 21814457 in words is "twenty-one million, eight hundred fourteen thousand, four hundred fifty-seven".