20111320121 has 4 divisors (see below), whose sum is σ = 20337290100. Its totient is φ = 19885350144.

The previous prime is 20111320111. The next prime is 20111320139. The reversal of 20111320121 is 12102311102.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 3752910121 + 16358410000 = 61261^2 + 127900^2 .

It is a cyclic number.

It is not a de Polignac number, because 20111320121 - 2¹⁸ = 20111057977 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20111320096 and 20111320105.

It is not an unprimeable number, because it can be changed into a prime (20111320111) 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, 112984856 + ... + 112985033.

It is an arithmetic number, because the mean of its divisors is an integer number (5084322525).

Almost surely, 2^20111320121 is an apocalyptic number.

It is an amenable number.

20111320121 is a deficient number, since it is larger than the sum of its proper divisors (225969979).

20111320121 is an equidigital number, since it uses as much as digits as its factorization.

20111320121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 225969978.

The product of its (nonzero) digits is 24, while the sum is 14.

Adding to 20111320121 its reverse (12102311102), we get a palindrome (32213631223).

The spelling of 20111320121 in words is "twenty billion, one hundred eleven million, three hundred twenty thousand, one hundred twenty-one".