21814420 has 12 divisors (see below), whose sum is σ = 45810324. Its totient is φ = 8725760.

The previous prime is 21814399. The next prime is 21814433. The reversal of 21814420 is 2441812.

It can be written as a sum of positive squares in 2 ways, for example, as 10227204 + 11587216 = 3198^2 + 3404^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21814391 and 21814400.

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, 545341 + ... + 545380.

It is an arithmetic number, because the mean of its divisors is an integer number (3817527).

Almost surely, 2^21814420 is an apocalyptic number.

21814420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21814420 is an abundant number, since it is smaller than the sum of its proper divisors (23995904).

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

21814420 is a wasteful number, since it uses less digits than its factorization.

21814420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1090730 (or 1090728 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 22.

The square root of 21814420 is about 4670.5909690316. The cubic root of 21814420 is about 279.4138247287.

The spelling of 21814420 in words is "twenty-one million, eight hundred fourteen thousand, four hundred twenty".