20012143121 has 4 divisors (see below), whose sum is σ = 20553011892. Its totient is φ = 19471274352.

The previous prime is 20012143103. The next prime is 20012143127. The reversal of 20012143121 is 12134121002.

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 18478324225 + 1533818896 = 135935^2 + 39164^2 .

It is a cyclic number.

It is not a de Polignac number, because 20012143121 - 2⁶ = 20012143057 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20012143121.

It is not an unprimeable number, because it can be changed into a prime (20012143127) 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, 270434330 + ... + 270434403.

It is an arithmetic number, because the mean of its divisors is an integer number (5138252973).

Almost surely, 2^20012143121 is an apocalyptic number.

It is an amenable number.

20012143121 is a deficient number, since it is larger than the sum of its proper divisors (540868771).

20012143121 is an equidigital number, since it uses as much as digits as its factorization.

20012143121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 540868770.

The product of its (nonzero) digits is 96, while the sum is 17.

Adding to 20012143121 its reverse (12134121002), we get a palindrome (32146264123).

The spelling of 20012143121 in words is "twenty billion, twelve million, one hundred forty-three thousand, one hundred twenty-one".