21111321204400 has 240 divisors, whose sum is σ = 58191633872064. Its totient is φ = 7209973923840.

The previous prime is 21111321204377. The next prime is 21111321204401. The reversal of 21111321204400 is 440212311112.

It is not an unprimeable number, because it can be changed into a prime (21111321204401) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2146981884 + ... + 2146991716.

Almost surely, 2^{21111321204400} is an apocalyptic number.

21111321204400 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 21111321204400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29095816936032).

21111321204400 is an abundant number, since it is smaller than the sum of its proper divisors (37080312667664).

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

21111321204400 is a wasteful number, since it uses less digits than its factorization.

21111321204400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12768 (or 12757 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 22.

Adding to 21111321204400 its reverse (440212311112), we get a palindrome (21551533515512).

The spelling of 21111321204400 in words is "twenty-one trillion, one hundred eleven billion, three hundred twenty-one million, two hundred four thousand, four hundred".