20443002121 has 4 divisors (see below), whose sum is σ = 20483165700. Its totient is φ = 20402838544.

The previous prime is 20443002091. The next prime is 20443002131. The reversal of 20443002121 is 12120034402.

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 15180950521 + 5262051600 = 123211^2 + 72540^2 .

It is a cyclic number.

It is not a de Polignac number, because 20443002121 - 2⁵ = 20443002089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20443002131) 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, 20081026 + ... + 20082043.

It is an arithmetic number, because the mean of its divisors is an integer number (5120791425).

Almost surely, 2^20443002121 is an apocalyptic number.

It is an amenable number.

20443002121 is a deficient number, since it is larger than the sum of its proper divisors (40163579).

20443002121 is an equidigital number, since it uses as much as digits as its factorization.

20443002121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40163578.

The product of its (nonzero) digits is 384, while the sum is 19.

Adding to 20443002121 its reverse (12120034402), we get a palindrome (32563036523).

The spelling of 20443002121 in words is "twenty billion, four hundred forty-three million, two thousand, one hundred twenty-one".