21231405200 has 30 divisors (see below), whose sum is σ = 51008451954. Its totient is φ = 8492561920.

The previous prime is 21231405193. The next prime is 21231405241. The reversal of 21231405200 is 250413212.

It can be written as a sum of positive squares in 3 ways, for example, as 5624400016 + 15607005184 = 74996^2 + 124928^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 26538857 + ... + 26539656.

Almost surely, 2^21231405200 is an apocalyptic number.

21231405200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21231405200 is an abundant number, since it is smaller than the sum of its proper divisors (29777046754).

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

21231405200 is a wasteful number, since it uses less digits than its factorization.

21231405200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53078531 (or 53078520 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 20.

Adding to 21231405200 its reverse (250413212), we get a palindrome (21481818412).

The spelling of 21231405200 in words is "twenty-one billion, two hundred thirty-one million, four hundred five thousand, two hundred".