18806861 has 2 divisors, whose sum is σ = 18806862. Its totient is φ = 18806860.

The previous prime is 18806831. The next prime is 18806869. The reversal of 18806861 is 16860881.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18541636 + 265225 = 4306^2 + 515^2 .It is also a bemirp because it and its reverse can be mirrored producing other two distinct primes, 19890881 and 18809891.

It is a cyclic number.

It is not a de Polignac number, because 18806861 - 2⁶ = 18806797 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18806869) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9403430 + 9403431.

It is an arithmetic number, because the mean of its divisors is an integer number (9403431).

Almost surely, 2^18806861 is an apocalyptic number.

It is an amenable number.

18806861 is a deficient number, since it is larger than the sum of its proper divisors (1).

18806861 is an equidigital number, since it uses as much as digits as its factorization.

18806861 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18432, while the sum is 38.

The square root of 18806861 is about 4336.6877913910. The cubic root of 18806861 is about 265.9329216354.

The spelling of 18806861 in words is "eighteen million, eight hundred six thousand, eight hundred sixty-one".