21203022400 has 168 divisors, whose sum is σ = 59731534080. Its totient is φ = 7256739840.

The previous prime is 21203022389. The next prime is 21203022403. The reversal of 21203022400 is 422030212.

It is a Harshad number since it is a multiple of its sum of digits (16).

It is not an unprimeable number, because it can be changed into a prime (21203022403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8051484 + ... + 8054116.

Almost surely, 2^21203022400 is an apocalyptic number.

21203022400 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 21203022400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29865767040).

21203022400 is an abundant number, since it is smaller than the sum of its proper divisors (38528511680).

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

21203022400 is a wasteful number, since it uses less digits than its factorization.

21203022400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3381 (or 3366 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 16.

Adding to 21203022400 its reverse (422030212), we get a palindrome (21625052612).

The spelling of 21203022400 in words is "twenty-one billion, two hundred three million, twenty-two thousand, four hundred".