21204341345 has 16 divisors (see below), whose sum is σ = 28149379200. Its totient is φ = 15204134400.

The previous prime is 21204341311. The next prime is 21204341387. The reversal of 21204341345 is 54314340212.

It is not a de Polignac number, because 21204341345 - 2¹⁶ = 21204275809 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2711120 + ... + 2718929.

It is an arithmetic number, because the mean of its divisors is an integer number (1759336200).

Almost surely, 2^21204341345 is an apocalyptic number.

It is an amenable number.

21204341345 is a deficient number, since it is larger than the sum of its proper divisors (6945037855).

21204341345 is a wasteful number, since it uses less digits than its factorization.

21204341345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5430136.

The product of its (nonzero) digits is 11520, while the sum is 29.

Adding to 21204341345 its reverse (54314340212), we get a palindrome (75518681557).

The spelling of 21204341345 in words is "twenty-one billion, two hundred four million, three hundred forty-one thousand, three hundred forty-five".