21423202400 has 72 divisors (see below), whose sum is σ = 52438128120. Its totient is φ = 8546549760.

The previous prime is 21423202343. The next prime is 21423202417. The reversal of 21423202400 is 420232412.

It is a Harshad number since it is a multiple of its sum of digits (20).

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, 267872 + ... + 338528.

It is an arithmetic number, because the mean of its divisors is an integer number (728307335).

Almost surely, 2^21423202400 is an apocalyptic number.

21423202400 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 21423202400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26219064060).

21423202400 is an abundant number, since it is smaller than the sum of its proper divisors (31014925720).

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

21423202400 is a wasteful number, since it uses less digits than its factorization.

21423202400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71056 (or 71043 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 20.

Adding to 21423202400 its reverse (420232412), we get a palindrome (21843434812).

The spelling of 21423202400 in words is "twenty-one billion, four hundred twenty-three million, two hundred two thousand, four hundred".