21200020312 has 16 divisors (see below), whose sum is σ = 39774705840. Its totient is φ = 10593432096.

The previous prime is 21200020297. The next prime is 21200020321. The reversal of 21200020312 is 21302000212.

It is a super-2 number, since 2×21200020312² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21200020292 and 21200020301.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 808548 + ... + 834355.

It is an arithmetic number, because the mean of its divisors is an integer number (2485919115).

Almost surely, 2^21200020312 is an apocalyptic number.

It is an amenable number.

21200020312 is a deficient number, since it is larger than the sum of its proper divisors (18574685528).

21200020312 is a wasteful number, since it uses less digits than its factorization.

21200020312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1644522 (or 1644518 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 13.

Adding to 21200020312 its reverse (21302000212), we get a palindrome (42502020524).

The spelling of 21200020312 in words is "twenty-one billion, two hundred million, twenty thousand, three hundred twelve".