21321320212 has 12 divisors (see below), whose sum is σ = 39276116320. Its totient is φ = 10099572696.

The previous prime is 21321320201. The next prime is 21321320239. The reversal of 21321320212 is 21202312312.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is a self number, because there is not a number n which added to its sum of digits gives 21321320212.

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, 140271768 + ... + 140271919.

Almost surely, 2^21321320212 is an apocalyptic number.

It is an amenable number.

21321320212 is a deficient number, since it is larger than the sum of its proper divisors (17954796108).

21321320212 is a wasteful number, since it uses less digits than its factorization.

21321320212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 280543710 (or 280543708 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 21321320212 its reverse (21202312312), we get a palindrome (42523632524).

The spelling of 21321320212 in words is "twenty-one billion, three hundred twenty-one million, three hundred twenty thousand, two hundred twelve".