21011031312 has 40 divisors (see below), whose sum is σ = 54692853600. Its totient is φ = 6950211840.

The previous prime is 21011031299. The next prime is 21011031329. The reversal of 21011031312 is 21313011012.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21011031291 and 21011031300.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1664437 + ... + 1677012.

It is an arithmetic number, because the mean of its divisors is an integer number (1367321340).

Almost surely, 2^21011031312 is an apocalyptic number.

It is an amenable number.

21011031312 is an abundant number, since it is smaller than the sum of its proper divisors (33681822288).

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

21011031312 is a wasteful number, since it uses less digits than its factorization.

21011031312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3341591 (or 3341585 counting only the distinct ones).

The product of its (nonzero) digits is 36, while the sum is 15.

Adding to 21011031312 its reverse (21313011012), we get a palindrome (42324042324).

The spelling of 21011031312 in words is "twenty-one billion, eleven million, thirty-one thousand, three hundred twelve".