21111211012 has 12 divisors (see below), whose sum is σ = 37000515916. Its totient is φ = 10539635040.

The previous prime is 21111211003. The next prime is 21111211013. The reversal of 21111211012 is 21011211112.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 17608228416 + 3502982596 = 132696^2 + 59186^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21111210983 and 21111211001.

It is not an unprimeable number, because it can be changed into a prime (21111211013) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3989643 + ... + 3994930.

Almost surely, 2^21111211012 is an apocalyptic number.

It is an amenable number.

21111211012 is a deficient number, since it is larger than the sum of its proper divisors (15889304904).

21111211012 is a wasteful number, since it uses less digits than its factorization.

21111211012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7985238 (or 7985236 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 21111211012 its reverse (21011211112), we get a palindrome (42122422124).

The spelling of 21111211012 in words is "twenty-one billion, one hundred eleven million, two hundred eleven thousand, twelve".