21231121312 has 12 divisors (see below), whose sum is σ = 41798770146. Its totient is φ = 10615560640.

The previous prime is 21231121259. The next prime is 21231121333. The reversal of 21231121312 is 21312113212.

It can be written as a sum of positive squares in only one way, i.e., 21060975376 + 170145936 = 145124^2 + 13044^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21231121312.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 331736239 + ... + 331736302.

Almost surely, 2^21231121312 is an apocalyptic number.

It is an amenable number.

21231121312 is a deficient number, since it is larger than the sum of its proper divisors (20567648834).

21231121312 is an equidigital number, since it uses as much as digits as its factorization.

21231121312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 663472551 (or 663472543 counting only the distinct ones).

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

Adding to 21231121312 its reverse (21312113212), we get a palindrome (42543234524).

The spelling of 21231121312 in words is "twenty-one billion, two hundred thirty-one million, one hundred twenty-one thousand, three hundred twelve".