21012012111100 has 72 divisors (see below), whose sum is σ = 46458216983808. Its totient is φ = 8245895673600.

The previous prime is 21012012111061. The next prime is 21012012111113. The reversal of 21012012111100 is 111121021012.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 166340965 + ... + 166467235.

It is an arithmetic number, because the mean of its divisors is an integer number (645253013664).

Almost surely, 2^{21012012111100} is an apocalyptic number.

21012012111100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21012012111100 is an abundant number, since it is smaller than the sum of its proper divisors (25446204872708).

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

21012012111100 is a wasteful number, since it uses less digits than its factorization.

21012012111100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 157735 (or 157728 counting only the distinct ones).

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

Adding to 21012012111100 its reverse (111121021012), we get a palindrome (21123133132112).

The spelling of 21012012111100 in words is "twenty-one trillion, twelve billion, twelve million, one hundred eleven thousand, one hundred".