21211231312 has 40 divisors (see below), whose sum is σ = 41214877704. Its totient is φ = 10575189504.

The previous prime is 21211231259. The next prime is 21211231319. The reversal of 21211231312 is 21313211212.

It can be written as a sum of positive squares in 4 ways, for example, as 1889119296 + 19322112016 = 43464^2 + 139004^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21211231312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21211231319) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12527938 + ... + 12529630.

Almost surely, 2^21211231312 is an apocalyptic number.

It is an amenable number.

21211231312 is a deficient number, since it is larger than the sum of its proper divisors (20003646392).

21211231312 is a wasteful number, since it uses less digits than its factorization.

21211231312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3487 (or 3481 counting only the distinct ones).

The product of its digits is 144, while the sum is 19.

Adding to 21211231312 its reverse (21313211212), we get a palindrome (42524442524).

The spelling of 21211231312 in words is "twenty-one billion, two hundred eleven million, two hundred thirty-one thousand, three hundred twelve".