20860181 has 4 divisors (see below), whose sum is σ = 20876172. Its totient is φ = 20844192.

The previous prime is 20860171. The next prime is 20860183. The reversal of 20860181 is 18106802.

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 10297681 + 10562500 = 3209^2 + 3250^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20860181 is a prime.

It is a super-2 number, since 2×20860181² = 870294302705522, which 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 20860181.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20860183) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5846 + ... + 8711.

It is an arithmetic number, because the mean of its divisors is an integer number (5219043).

Almost surely, 2^20860181 is an apocalyptic number.

It is an amenable number.

20860181 is a deficient number, since it is larger than the sum of its proper divisors (15991).

20860181 is a wasteful number, since it uses less digits than its factorization.

20860181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15990.

The product of its (nonzero) digits is 768, while the sum is 26.

The square root of 20860181 is about 4567.2947135038. The cubic root of 20860181 is about 275.2787520600.

Adding to 20860181 its reverse (18106802), we get a palindrome (38966983).

The spelling of 20860181 in words is "twenty million, eight hundred sixty thousand, one hundred eighty-one".