21131236223 has 8 divisors (see below), whose sum is σ = 22256062848. Its totient is φ = 20023582744.

The previous prime is 21131236219. The next prime is 21131236267. The reversal of 21131236223 is 32263213112.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21131236223 - 2² = 21131236219 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21131236192 and 21131236201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21131230223) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4290761 + ... + 4295682.

It is an arithmetic number, because the mean of its divisors is an integer number (2782007856).

Almost surely, 2^21131236223 is an apocalyptic number.

21131236223 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

21131236223 is a deficient number, since it is larger than the sum of its proper divisors (1124826625).

21131236223 is a wasteful number, since it uses less digits than its factorization.

21131236223 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8586573.

The product of its digits is 2592, while the sum is 26.

Adding to 21131236223 its reverse (32263213112), we get a palindrome (53394449335).

The spelling of 21131236223 in words is "twenty-one billion, one hundred thirty-one million, two hundred thirty-six thousand, two hundred twenty-three".