20121200111021 has 4 divisors (see below), whose sum is σ = 21180210643200. Its totient is φ = 19062189578844.

The previous prime is 20121200110987. The next prime is 20121200111063. The reversal of 20121200111021 is 12011100212102.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20121200111021 - 2¹⁴ = 20121200094637 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20121200110987 and 20121200111005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20121200111071) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 529505266061 + ... + 529505266098.

It is an arithmetic number, because the mean of its divisors is an integer number (5295052660800).

Almost surely, 2^{20121200111021} is an apocalyptic number.

It is an amenable number.

20121200111021 is a deficient number, since it is larger than the sum of its proper divisors (1059010532179).

20121200111021 is a wasteful number, since it uses less digits than its factorization.

20121200111021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1059010532178.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 20121200111021 its reverse (12011100212102), we get a palindrome (32132300323123).

The spelling of 20121200111021 in words is "twenty trillion, one hundred twenty-one billion, two hundred million, one hundred eleven thousand, twenty-one".