21468420 has 72 divisors (see below), whose sum is σ = 66732120. Its totient is φ = 5583360.

The previous prime is 21468413. The next prime is 21468431. The reversal of 21468420 is 2486412.

It can be written as a sum of positive squares in 4 ways, for example, as 1272384 + 20196036 = 1128^2 + 4494^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5926 + ... + 8834.

It is an arithmetic number, because the mean of its divisors is an integer number (926835).

Almost surely, 2^21468420 is an apocalyptic number.

21468420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21468420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33366060).

21468420 is an abundant number, since it is smaller than the sum of its proper divisors (45263700).

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

21468420 is a wasteful number, since it uses less digits than its factorization.

21468420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2965 (or 2960 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 27.

The square root of 21468420 is about 4633.4026373714. The cubic root of 21468420 is about 277.9286775956.

The spelling of 21468420 in words is "twenty-one million, four hundred sixty-eight thousand, four hundred twenty".