21822420 has 48 divisors (see below), whose sum is σ = 61322688. Its totient is φ = 5798400.

The previous prime is 21822403. The next prime is 21822421. The reversal of 21822420 is 2422812.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21822421) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23607 + ... + 24513.

It is an arithmetic number, because the mean of its divisors is an integer number (1277556).

Almost surely, 2^21822420 is an apocalyptic number.

21822420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21822420 is an abundant number, since it is smaller than the sum of its proper divisors (39500268).

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

21822420 is a wasteful number, since it uses less digits than its factorization.

21822420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1320 (or 1318 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 21.

The square root of 21822420 is about 4671.4473131996. The cubic root of 21822420 is about 279.4479770219.

The spelling of 21822420 in words is "twenty-one million, eight hundred twenty-two thousand, four hundred twenty".