21212123030312 has 16 divisors (see below), whose sum is σ = 39785523501300. Its totient is φ = 10602650096640.

The previous prime is 21212123030279. The next prime is 21212123030321. The reversal of 21212123030312 is 21303032121212.

It can be written as a sum of positive squares in 2 ways, for example, as 18036720205156 + 3175402825156 = 4246966^2 + 1781966^2 .

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, 426400889 + ... + 426450632.

Almost surely, 2^{21212123030312} is an apocalyptic number.

It is an amenable number.

21212123030312 is a deficient number, since it is larger than the sum of its proper divisors (18573400470988).

21212123030312 is a wasteful number, since it uses less digits than its factorization.

21212123030312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 852854636 (or 852854632 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 23.

Adding to 21212123030312 its reverse (21303032121212), we get a palindrome (42515155151524).

The spelling of 21212123030312 in words is "twenty-one trillion, two hundred twelve billion, one hundred twenty-three million, thirty thousand, three hundred twelve".