21203134400 has 336 divisors, whose sum is σ = 63570770496. Its totient is φ = 6794772480.

The previous prime is 21203134369. The next prime is 21203134411. The reversal of 21203134400 is 443130212.

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 pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 36746912 + ... + 36747488.

Almost surely, 2^21203134400 is an apocalyptic number.

21203134400 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 21203134400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31785385248).

21203134400 is an abundant number, since it is smaller than the sum of its proper divisors (42367636096).

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

21203134400 is a wasteful number, since it uses less digits than its factorization.

21203134400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 816 (or 801 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 20.

Adding to 21203134400 its reverse (443130212), we get a palindrome (21646264612).

The spelling of 21203134400 in words is "twenty-one billion, two hundred three million, one hundred thirty-four thousand, four hundred".