18617973013 has 4 divisors (see below), whose sum is σ = 18639106668. Its totient is φ = 18596839360.

The previous prime is 18617973007. The next prime is 18617973037. The reversal of 18617973013 is 31037971681.

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

It can be written as a sum of positive squares in 2 ways, for example, as 8825287249 + 9792685764 = 93943^2 + 98958^2 .

It is a cyclic number.

It is not a de Polignac number, because 18617973013 - 2²⁹ = 18081102101 is a prime.

It is a super-2 number, since 2×18617973013² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18617973043) 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, 10565506 + ... + 10567267.

It is an arithmetic number, because the mean of its divisors is an integer number (4659776667).

Almost surely, 2^18617973013 is an apocalyptic number.

It is an amenable number.

18617973013 is a deficient number, since it is larger than the sum of its proper divisors (21133655).

18617973013 is an equidigital number, since it uses as much as digits as its factorization.

18617973013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21133654.

The product of its (nonzero) digits is 190512, while the sum is 46.

The spelling of 18617973013 in words is "eighteen billion, six hundred seventeen million, nine hundred seventy-three thousand, thirteen".