21234121400 has 96 divisors (see below), whose sum is σ = 51528733200. Its totient is φ = 8129971200.

The previous prime is 21234121397. The next prime is 21234121421. The reversal of 21234121400 is 412143212.

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 23 ways as a sum of consecutive naturals, for example, 410171 + ... + 459029.

Almost surely, 2^21234121400 is an apocalyptic number.

21234121400 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 21234121400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25764366600).

21234121400 is an abundant number, since it is smaller than the sum of its proper divisors (30294611800).

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

21234121400 is a wasteful number, since it uses less digits than its factorization.

21234121400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48969 (or 48960 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 20.

Adding to 21234121400 its reverse (412143212), we get a palindrome (21646264612).

The spelling of 21234121400 in words is "twenty-one billion, two hundred thirty-four million, one hundred twenty-one thousand, four hundred".