21200423 has 4 divisors (see below), whose sum is σ = 21438720. Its totient is φ = 20962128.

The previous prime is 21200401. The next prime is 21200461. The reversal of 21200423 is 32400212.

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 21200423 - 2¹² = 21196327 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21200398 and 21200407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21200623) 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, 119015 + ... + 119192.

It is an arithmetic number, because the mean of its divisors is an integer number (5359680).

Almost surely, 2^21200423 is an apocalyptic number.

21200423 is a deficient number, since it is larger than the sum of its proper divisors (238297).

21200423 is an equidigital number, since it uses as much as digits as its factorization.

21200423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 238296.

The product of its (nonzero) digits is 96, while the sum is 14.

The square root of 21200423 is about 4604.3917079241. The cubic root of 21200423 is about 276.7673414683.

Adding to 21200423 its reverse (32400212), we get a palindrome (53600635).

The spelling of 21200423 in words is "twenty-one million, two hundred thousand, four hundred twenty-three".