21345164513 has 4 divisors (see below), whose sum is σ = 22273215168. Its totient is φ = 20417113860.

The previous prime is 21345164443. The next prime is 21345164549. The reversal of 21345164513 is 31546154312.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21345164513 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21345164593) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 464025293 + ... + 464025338.

It is an arithmetic number, because the mean of its divisors is an integer number (5568303792).

Almost surely, 2^21345164513 is an apocalyptic number.

21345164513 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

21345164513 is a deficient number, since it is larger than the sum of its proper divisors (928050655).

21345164513 is an equidigital number, since it uses as much as digits as its factorization.

21345164513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 928050654.

The product of its digits is 43200, while the sum is 35.

The spelling of 21345164513 in words is "twenty-one billion, three hundred forty-five million, one hundred sixty-four thousand, five hundred thirteen".