21201230423 has 16 divisors (see below), whose sum is σ = 21792291840. Its totient is φ = 20616310176.

The previous prime is 21201230381. The next prime is 21201230437. The reversal of 21201230423 is 32403210212.

It is a cyclic number.

It is not a de Polignac number, because 21201230423 - 2⁶ = 21201230359 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21201230395 and 21201230404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21201230443) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10396838 + ... + 10398876.

It is an arithmetic number, because the mean of its divisors is an integer number (1362018240).

Almost surely, 2^21201230423 is an apocalyptic number.

21201230423 is a deficient number, since it is larger than the sum of its proper divisors (591061417).

21201230423 is a wasteful number, since it uses less digits than its factorization.

21201230423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3406.

The product of its (nonzero) digits is 576, while the sum is 20.

Adding to 21201230423 its reverse (32403210212), we get a palindrome (53604440635).

The spelling of 21201230423 in words is "twenty-one billion, two hundred one million, two hundred thirty thousand, four hundred twenty-three".