21012111111020 has 48 divisors (see below), whose sum is σ = 44148338492160. Its totient is φ = 8400482737344.

The previous prime is 21012111110989. The next prime is 21012111111053. The reversal of 21012111111020 is 2011111121012.

It is a junction number, because it is equal to n+sod(n) for n = 21012111110986 and 21012111111004.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 319693721 + ... + 319759439.

It is an arithmetic number, because the mean of its divisors is an integer number (919757051920).

Almost surely, 2^{21012111111020} is an apocalyptic number.

21012111111020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21012111111020 is an abundant number, since it is smaller than the sum of its proper divisors (23136227381140).

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

21012111111020 is a wasteful number, since it uses less digits than its factorization.

21012111111020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73782 (or 73780 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 14.

Adding to 21012111111020 its reverse (2011111121012), we get a palindrome (23023222232032).

The spelling of 21012111111020 in words is "twenty-one trillion, twelve billion, one hundred eleven million, one hundred eleven thousand, twenty".