21033352423 has 4 divisors (see below), whose sum is σ = 21056240560. Its totient is φ = 21010464288.

The previous prime is 21033352387. The next prime is 21033352453. The reversal of 21033352423 is 32425333012.

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 21033352423 - 2¹⁷ = 21033221351 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21033352391 and 21033352400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21033352453) 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, 11442690 + ... + 11444527.

It is an arithmetic number, because the mean of its divisors is an integer number (5264060140).

Almost surely, 2^21033352423 is an apocalyptic number.

21033352423 is a deficient number, since it is larger than the sum of its proper divisors (22888137).

21033352423 is an equidigital number, since it uses as much as digits as its factorization.

21033352423 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22888136.

The product of its (nonzero) digits is 12960, while the sum is 28.

Adding to 21033352423 its reverse (32425333012), we get a palindrome (53458685435).

The spelling of 21033352423 in words is "twenty-one billion, thirty-three million, three hundred fifty-two thousand, four hundred twenty-three".