21143234423 has 4 divisors (see below), whose sum is σ = 21143987208. Its totient is φ = 21142481640.

The previous prime is 21143234419. The next prime is 21143234429. The reversal of 21143234423 is 32443234112.

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

It is a cyclic number.

It is not a de Polignac number, because 21143234423 - 2² = 21143234419 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 (21143234429) 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, 332561 + ... + 391002.

It is an arithmetic number, because the mean of its divisors is an integer number (5285996802).

Almost surely, 2^21143234423 is an apocalyptic number.

21143234423 is a deficient number, since it is larger than the sum of its proper divisors (752785).

21143234423 is an equidigital number, since it uses as much as digits as its factorization.

21143234423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 752784.

The product of its digits is 13824, while the sum is 29.

Adding to 21143234423 its reverse (32443234112), we get a palindrome (53586468535).

The spelling of 21143234423 in words is "twenty-one billion, one hundred forty-three million, two hundred thirty-four thousand, four hundred twenty-three".