21311201212 has 12 divisors (see below), whose sum is σ = 42622402480. Its totient is φ = 9133371936.

The previous prime is 21311201179. The next prime is 21311201221. The reversal of 21311201212 is 21210211312.

21311201212 is an admirable number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 380557137 + ... + 380557192.

Almost surely, 2^21311201212 is an apocalyptic number.

It is an amenable number.

21311201212 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21311201212 is a wasteful number, since it uses less digits than its factorization.

21311201212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 761114340 (or 761114338 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 16.

Adding to 21311201212 its reverse (21210211312), we get a palindrome (42521412524).

The spelling of 21311201212 in words is "twenty-one billion, three hundred eleven million, two hundred one thousand, two hundred twelve".