21211311400 has 96 divisors (see below), whose sum is σ = 52629488640. Its totient is φ = 7922396160.

The previous prime is 21211311391. The next prime is 21211311403. The reversal of 21211311400 is 411311212.

It is not an unprimeable number, because it can be changed into a prime (21211311403) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 407239 + ... + 456361.

It is an arithmetic number, because the mean of its divisors is an integer number (548223840).

Almost surely, 2^21211311400 is an apocalyptic number.

21211311400 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 21211311400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26314744320).

21211311400 is an abundant number, since it is smaller than the sum of its proper divisors (31418177240).

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

21211311400 is a wasteful number, since it uses less digits than its factorization.

21211311400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49283 (or 49274 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 16.

Adding to 21211311400 its reverse (411311212), we get a palindrome (21622622612).

The spelling of 21211311400 in words is "twenty-one billion, two hundred eleven million, three hundred eleven thousand, four hundred".