21203130400 has 36 divisors (see below), whose sum is σ = 51762144042. Its totient is φ = 8481251840.

The previous prime is 21203130397. The next prime is 21203130457. The reversal of 21203130400 is 403130212.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 11838310416 + 9364819984 = 108804^2 + 96772^2 .

It is a Harshad number since it is a multiple of its sum of digits (16).

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, 13251157 + ... + 13252756.

Almost surely, 2^21203130400 is an apocalyptic number.

21203130400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21203130400 is an abundant number, since it is smaller than the sum of its proper divisors (30559013642).

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

21203130400 is a wasteful number, since it uses less digits than its factorization.

21203130400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26503933 (or 26503920 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 16.

Adding to 21203130400 its reverse (403130212), we get a palindrome (21606260612).

The spelling of 21203130400 in words is "twenty-one billion, two hundred three million, one hundred thirty thousand, four hundred".