21468940 has 12 divisors (see below), whose sum is σ = 45084816. Its totient is φ = 8587568.

The previous prime is 21468929. The next prime is 21468947. The reversal of 21468940 is 4986412.

It is a junction number, because it is equal to n+sod(n) for n = 21468896 and 21468905.

It is not an unprimeable number, because it can be changed into a prime (21468947) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 536704 + ... + 536743.

It is an arithmetic number, because the mean of its divisors is an integer number (3757068).

Almost surely, 2^21468940 is an apocalyptic number.

21468940 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21468940 is an abundant number, since it is smaller than the sum of its proper divisors (23615876).

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

21468940 is a wasteful number, since it uses less digits than its factorization.

21468940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1073456 (or 1073454 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 34.

The square root of 21468940 is about 4633.4587513002. The cubic root of 21468940 is about 277.9309215388.

The spelling of 21468940 in words is "twenty-one million, four hundred sixty-eight thousand, nine hundred forty".