21422400 has 84 divisors (see below), whose sum is σ = 70299072. Its totient is φ = 5711360.

The previous prime is 21422399. The next prime is 21422411. The reversal of 21422400 is 422412.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 21422400.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2569 + ... + 7031.

Almost surely, 2^21422400 is an apocalyptic number.

21422400 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 21422400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35149536).

21422400 is an abundant number, since it is smaller than the sum of its proper divisors (48876672).

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

21422400 is a wasteful number, since it uses less digits than its factorization.

21422400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4488 (or 4473 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 15.

The square root of 21422400 is about 4628.4338603895. The cubic root of 21422400 is about 277.7299449489.

Adding to 21422400 its reverse (422412), we get a palindrome (21844812).

The spelling of 21422400 in words is "twenty-one million, four hundred twenty-two thousand, four hundred".