16860072181 has 4 divisors (see below), whose sum is σ = 16861406572. Its totient is φ = 16858737792.

The previous prime is 16860072179. The next prime is 16860072197. The reversal of 16860072181 is 18127006861.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18127006861 = 503 ⋅36037787.

It can be written as a sum of positive squares in 2 ways, for example, as 4015249956 + 12844822225 = 63366^2 + 113335^2 .

It is a cyclic number.

It is not a de Polignac number, because 16860072181 - 2¹ = 16860072179 is a prime.

It is a super-2 number, since 2×16860072181² (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 (16860022181) 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, 648060 + ... + 673573.

It is an arithmetic number, because the mean of its divisors is an integer number (4215351643).

Almost surely, 2^16860072181 is an apocalyptic number.

It is an amenable number.

16860072181 is a deficient number, since it is larger than the sum of its proper divisors (1334391).

16860072181 is a wasteful number, since it uses less digits than its factorization.

16860072181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1334390.

The product of its (nonzero) digits is 32256, while the sum is 40.

The spelling of 16860072181 in words is "sixteen billion, eight hundred sixty million, seventy-two thousand, one hundred eighty-one".