21132454400 has 120 divisors (see below), whose sum is σ = 52488186300. Its totient is φ = 8431861760.

The previous prime is 21132454391. The next prime is 21132454439. The reversal of 21132454400 is 445423112.

It can be written as a sum of positive squares in 6 ways, for example, as 12121129216 + 9011325184 = 110096^2 + 94928^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21132454400.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5745362 + ... + 5749038.

Almost surely, 2^21132454400 is an apocalyptic number.

21132454400 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 21132454400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26244093150).

21132454400 is an abundant number, since it is smaller than the sum of its proper divisors (31355731900).

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

21132454400 is an equidigital number, since it uses as much as digits as its factorization.

21132454400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4154 (or 4133 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 26.

Adding to 21132454400 its reverse (445423112), we get a palindrome (21577877512).

The spelling of 21132454400 in words is "twenty-one billion, one hundred thirty-two million, four hundred fifty-four thousand, four hundred".