21240422400 has 336 divisors, whose sum is σ = 70988456448. Its totient is φ = 5603328000.

The previous prime is 21240422377. The next prime is 21240422417. The reversal of 21240422400 is 422404212.

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, 111206305 + ... + 111206495.

It is an arithmetic number, because the mean of its divisors is an integer number (211275168).

Almost surely, 2^21240422400 is an apocalyptic number.

21240422400 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 21240422400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35494228224).

21240422400 is an abundant number, since it is smaller than the sum of its proper divisors (49748034048).

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

21240422400 is a wasteful number, since it uses less digits than its factorization.

21240422400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 411 (or 382 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 21.

Adding to 21240422400 its reverse (422404212), we get a palindrome (21662826612).

The spelling of 21240422400 in words is "twenty-one billion, two hundred forty million, four hundred twenty-two thousand, four hundred".