21230131212 has 48 divisors (see below), whose sum is σ = 55091836800. Its totient is φ = 7070184720.

The previous prime is 21230131211. The next prime is 21230131217. The reversal of 21230131212 is 21213103212.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (21230131211) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27739 + ... + 207917.

It is an arithmetic number, because the mean of its divisors is an integer number (1147746600).

Almost surely, 2^21230131212 is an apocalyptic number.

It is an amenable number.

21230131212 is an abundant number, since it is smaller than the sum of its proper divisors (33861705588).

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

21230131212 is a wasteful number, since it uses less digits than its factorization.

21230131212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 181283 (or 181275 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 21230131212 its reverse (21213103212), we get a palindrome (42443234424).

The spelling of 21230131212 in words is "twenty-one billion, two hundred thirty million, one hundred thirty-one thousand, two hundred twelve".