20123231143421 has 4 divisors (see below), whose sum is σ = 22997978449632. Its totient is φ = 17248483837212.

The previous prime is 20123231143397. The next prime is 20123231143517. The reversal of 20123231143421 is 12434113232102.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20123231143421 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 (20123231145421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1437373653095 + ... + 1437373653108.

It is an arithmetic number, because the mean of its divisors is an integer number (5749494612408).

Almost surely, 2^{20123231143421} is an apocalyptic number.

It is an amenable number.

20123231143421 is a deficient number, since it is larger than the sum of its proper divisors (2874747306211).

20123231143421 is an equidigital number, since it uses as much as digits as its factorization.

20123231143421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2874747306210.

The product of its (nonzero) digits is 6912, while the sum is 29.

Adding to 20123231143421 its reverse (12434113232102), we get a palindrome (32557344375523).

The spelling of 20123231143421 in words is "twenty trillion, one hundred twenty-three billion, two hundred thirty-one million, one hundred forty-three thousand, four hundred twenty-one".