21340120323 has 4 divisors (see below), whose sum is σ = 28453493768. Its totient is φ = 14226746880.

The previous prime is 21340120309. The next prime is 21340120327. The reversal of 21340120323 is 32302104312.

It is a semiprime because it is the product of two primes.

It is a de Polignac number, because none of the positive numbers 2^k-21340120323 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 21340120323.

It is not an unprimeable number, because it can be changed into a prime (21340120327) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3556686718 + ... + 3556686723.

It is an arithmetic number, because the mean of its divisors is an integer number (7113373442).

Almost surely, 2^21340120323 is an apocalyptic number.

21340120323 is a deficient number, since it is larger than the sum of its proper divisors (7113373445).

21340120323 is an equidigital number, since it uses as much as digits as its factorization.

21340120323 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7113373444.

The product of its (nonzero) digits is 864, while the sum is 21.

Adding to 21340120323 its reverse (32302104312), we get a palindrome (53642224635).

The spelling of 21340120323 in words is "twenty-one billion, three hundred forty million, one hundred twenty thousand, three hundred twenty-three".