161718673867 has 4 divisors (see below), whose sum is σ = 161725104576. Its totient is φ = 161712243160.

The previous prime is 161718673843. The next prime is 161718673877. The reversal of 161718673867 is 768376817161.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 768376817161 = 577 ⋅1331675593.

It is a cyclic number.

It is not a de Polignac number, because 161718673867 - 2¹⁵ = 161718641099 is a prime.

It is a super-2 number, since 2×161718673867² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161718673817) 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, 3177484 + ... + 3227977.

It is an arithmetic number, because the mean of its divisors is an integer number (40431276144).

Almost surely, 2^161718673867 is an apocalyptic number.

161718673867 is a deficient number, since it is larger than the sum of its proper divisors (6430709).

161718673867 is an equidigital number, since it uses as much as digits as its factorization.

161718673867 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6430708.

The product of its digits is 14224896, while the sum is 61.

The spelling of 161718673867 in words is "one hundred sixty-one billion, seven hundred eighteen million, six hundred seventy-three thousand, eight hundred sixty-seven".