21335322400 has 144 divisors (see below), whose sum is σ = 59733301824. Its totient is φ = 7289441280.

The previous prime is 21335322389. The next prime is 21335322461. The reversal of 21335322400 is 422353312.

It is a Harshad number since it is a multiple of its sum of digits (25).

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, 1634299 + ... + 1647301.

It is an arithmetic number, because the mean of its divisors is an integer number (414814596).

Almost surely, 2^21335322400 is an apocalyptic number.

21335322400 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 21335322400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29866650912).

21335322400 is an abundant number, since it is smaller than the sum of its proper divisors (38397979424).

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

21335322400 is a wasteful number, since it uses less digits than its factorization.

21335322400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13323 (or 13310 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 25.

Adding to 21335322400 its reverse (422353312), we get a palindrome (21757675712).

The spelling of 21335322400 in words is "twenty-one billion, three hundred thirty-five million, three hundred twenty-two thousand, four hundred".