18216565373 has 4 divisors (see below), whose sum is σ = 19288128060. Its totient is φ = 17145002688.

The previous prime is 18216565369. The next prime is 18216565379. The reversal of 18216565373 is 37356561281.

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 7566738169 + 10649827204 = 86987^2 + 103198^2 .

It is a cyclic number.

It is not a de Polignac number, because 18216565373 - 2² = 18216565369 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18216565379) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 535781318 + ... + 535781351.

It is an arithmetic number, because the mean of its divisors is an integer number (4822032015).

Almost surely, 2^18216565373 is an apocalyptic number.

It is an amenable number.

18216565373 is a deficient number, since it is larger than the sum of its proper divisors (1071562687).

18216565373 is a wasteful number, since it uses less digits than its factorization.

18216565373 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1071562686.

The product of its digits is 907200, while the sum is 47.

The spelling of 18216565373 in words is "eighteen billion, two hundred sixteen million, five hundred sixty-five thousand, three hundred seventy-three".