21453431200 has 36 divisors (see below), whose sum is σ = 52373190870. Its totient is φ = 8581372160.

The previous prime is 21453431191. The next prime is 21453431227. The reversal of 21453431200 is 213435412.

It can be written as a sum of positive squares in 3 ways, for example, as 17647528336 + 3805902864 = 132844^2 + 61692^2 .

It is a Harshad number since it is a multiple of its sum of digits (25).

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, 13407595 + ... + 13409194.

Almost surely, 2^21453431200 is an apocalyptic number.

21453431200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21453431200 is an abundant number, since it is smaller than the sum of its proper divisors (30919759670).

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

21453431200 is a wasteful number, since it uses less digits than its factorization.

21453431200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26816809 (or 26816796 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 25.

Adding to 21453431200 its reverse (213435412), we get a palindrome (21666866612).

The spelling of 21453431200 in words is "twenty-one billion, four hundred fifty-three million, four hundred thirty-one thousand, two hundred".