21111220012 has 12 divisors (see below), whose sum is σ = 37496047960. Its totient is φ = 10398063456.

The previous prime is 21111220001. The next prime is 21111220037. The reversal of 21111220012 is 21002211112.

It is a super-2 number, since 2×21111220012² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21111219974 and 21111220001.

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, 39386337 + ... + 39386872.

Almost surely, 2^21111220012 is an apocalyptic number.

It is an amenable number.

21111220012 is a deficient number, since it is larger than the sum of its proper divisors (16384827948).

21111220012 is a wasteful number, since it uses less digits than its factorization.

21111220012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78773280 (or 78773278 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21111220012 its reverse (21002211112), we get a palindrome (42113431124).

The spelling of 21111220012 in words is "twenty-one billion, one hundred eleven million, two hundred twenty thousand, twelve".