21130230212 has 108 divisors (see below), whose sum is σ = 48186838980. Its totient is φ = 8070596352.

The previous prime is 21130230169. The next prime is 21130230271. The reversal of 21130230212 is 21203203112.

It can be written as a sum of positive squares in 6 ways, for example, as 1858127236 + 19272102976 = 43106^2 + 138824^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 949598 + ... + 971594.

It is an arithmetic number, because the mean of its divisors is an integer number (446174435).

Almost surely, 2^21130230212 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21130230212, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24093419490).

21130230212 is an abundant number, since it is smaller than the sum of its proper divisors (27056608768).

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

21130230212 is a wasteful number, since it uses less digits than its factorization.

21130230212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22070 (or 22048 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 17.

Adding to 21130230212 its reverse (21203203112), we get a palindrome (42333433324).

The spelling of 21130230212 in words is "twenty-one billion, one hundred thirty million, two hundred thirty thousand, two hundred twelve".