20404243123 has 4 divisors (see below), whose sum is σ = 22259174328. Its totient is φ = 18549311920.

The previous prime is 20404243039. The next prime is 20404243133. The reversal of 20404243123 is 32134240402.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20404243123 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20404243133) 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, 927465586 + ... + 927465607.

It is an arithmetic number, because the mean of its divisors is an integer number (5564793582).

Almost surely, 2^20404243123 is an apocalyptic number.

20404243123 is a deficient number, since it is larger than the sum of its proper divisors (1854931205).

20404243123 is a wasteful number, since it uses less digits than its factorization.

20404243123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1854931204.

The product of its (nonzero) digits is 4608, while the sum is 25.

Adding to 20404243123 its reverse (32134240402), we get a palindrome (52538483525).

The spelling of 20404243123 in words is "twenty billion, four hundred four million, two hundred forty-three thousand, one hundred twenty-three".