18560981 has 2 divisors, whose sum is σ = 18560982. Its totient is φ = 18560980.

The previous prime is 18560963. The next prime is 18561001. The reversal of 18560981 is 18906581.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12602500 + 5958481 = 3550^2 + 2441^2 .

It is an emirp because it is prime and its reverse (18906581) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18560981 - 2⁶ = 18560917 is a prime.

It is a super-3 number, since 3×18560981³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18560921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9280490 + 9280491.

It is an arithmetic number, because the mean of its divisors is an integer number (9280491).

Almost surely, 2^18560981 is an apocalyptic number.

It is an amenable number.

18560981 is a deficient number, since it is larger than the sum of its proper divisors (1).

18560981 is an equidigital number, since it uses as much as digits as its factorization.

18560981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 17280, while the sum is 38.

The square root of 18560981 is about 4308.2456986574. The cubic root of 18560981 is about 264.7689025967.

The spelling of 18560981 in words is "eighteen million, five hundred sixty thousand, nine hundred eighty-one".