718221857173 has 4 divisors (see below), whose sum is σ = 742988128140. Its totient is φ = 693455586208.

The previous prime is 718221857161. The next prime is 718221857281. The reversal of 718221857173 is 371758122817.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 371758122817 = 79 ⋅4705799023.

It can be written as a sum of positive squares in 2 ways, for example, as 174342156849 + 543879700324 = 417543^2 + 737482^2 .

It is a cyclic number.

It is not a de Polignac number, because 718221857173 - 2⁹ = 718221856661 is a prime.

It is a super-2 number, since 2×718221857173² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 718221857173.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (718221851173) 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, 12383135440 + ... + 12383135497.

It is an arithmetic number, because the mean of its divisors is an integer number (185747032035).

Almost surely, 2^718221857173 is an apocalyptic number.

It is an amenable number.

718221857173 is a deficient number, since it is larger than the sum of its proper divisors (24766270967).

718221857173 is a wasteful number, since it uses less digits than its factorization.

718221857173 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24766270966.

The product of its digits is 1317120, while the sum is 52.

The spelling of 718221857173 in words is "seven hundred eighteen billion, two hundred twenty-one million, eight hundred fifty-seven thousand, one hundred seventy-three".