21201103423 has 4 divisors (see below), whose sum is σ = 21456538488. Its totient is φ = 20945668360.

The previous prime is 21201103421. The next prime is 21201103439. The reversal of 21201103423 is 32430110212.

It is a happy number.

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 21201103423 - 2¹ = 21201103421 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21201103423.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21201103421) 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, 127717408 + ... + 127717573.

It is an arithmetic number, because the mean of its divisors is an integer number (5364134622).

Almost surely, 2^21201103423 is an apocalyptic number.

21201103423 is a deficient number, since it is larger than the sum of its proper divisors (255435065).

21201103423 is an equidigital number, since it uses as much as digits as its factorization.

21201103423 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 255435064.

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 21201103423 its reverse (32430110212), we get a palindrome (53631213635).

The spelling of 21201103423 in words is "twenty-one billion, two hundred one million, one hundred three thousand, four hundred twenty-three".