21130000000 has 128 divisors (see below), whose sum is σ = 52643419920. Its totient is φ = 8448000000.

The previous prime is 21129999991. The next prime is 21130000033. The reversal of 21130000000 is 3112.

It can be written as a sum of positive squares in 8 ways, for example, as 20964723264 + 165276736 = 144792^2 + 12856^2 .

It is a tau number, because it is divible by the number of its divisors (128).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9998944 + ... + 10001056.

Almost surely, 2^21130000000 is an apocalyptic number.

21130000000 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 21130000000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26321709960).

21130000000 is an abundant number, since it is smaller than the sum of its proper divisors (31513419920).

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

21130000000 is an frugal number, since it uses more digits than its factorization.

21130000000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2162 (or 2120 counting only the distinct ones).

The product of its (nonzero) digits is 6, while the sum is 7.

Adding to 21130000000 its reverse (3112), we get a palindrome (21130003112).

The spelling of 21130000000 in words is "twenty-one billion, one hundred thirty million", and thus it is an aban number.