20123421013 has 4 divisors (see below), whose sum is σ = 20124153868. Its totient is φ = 20122688160.

The previous prime is 20123420987. The next prime is 20123421023. The reversal of 20123421013 is 31012432102.

It is a happy number.

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 8471729764 + 11651691249 = 92042^2 + 107943^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20123421013 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20123421023) 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, 323568 + ... + 380713.

It is an arithmetic number, because the mean of its divisors is an integer number (5031038467).

Almost surely, 2^20123421013 is an apocalyptic number.

It is an amenable number.

20123421013 is a deficient number, since it is larger than the sum of its proper divisors (732855).

20123421013 is an equidigital number, since it uses as much as digits as its factorization.

20123421013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 732854.

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 20123421013 its reverse (31012432102), we get a palindrome (51135853115).

The spelling of 20123421013 in words is "twenty billion, one hundred twenty-three million, four hundred twenty-one thousand, thirteen".