8172738372818 has 4 divisors (see below), whose sum is σ = 12259107559230. Its totient is φ = 4086369186408.

The previous prime is 8172738372817. The next prime is 8172738372823. The reversal of 8172738372818 is 8182738372718.

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

It can be written as a sum of positive squares in only one way, i.e., 6893864630689 + 1278873742129 = 2625617^2 + 1130873^2 .

It is a super-2 number, since 2×8172738372818² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (8172738372817) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2043184593203 + ... + 2043184593206.

Almost surely, 2^{8172738372818} is an apocalyptic number.

8172738372818 is a deficient number, since it is larger than the sum of its proper divisors (4086369186412).

8172738372818 is a wasteful number, since it uses less digits than its factorization.

8172738372818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4086369186411.

The product of its digits is 50577408, while the sum is 65.

The spelling of 8172738372818 in words is "eight trillion, one hundred seventy-two billion, seven hundred thirty-eight million, three hundred seventy-two thousand, eight hundred eighteen".