18506869 has 2 divisors, whose sum is σ = 18506870. Its totient is φ = 18506868.

The previous prime is 18506849. The next prime is 18506903. The reversal of 18506869 is 96860581.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18164644 + 342225 = 4262^2 + 585^2 .

It is an emirp because it is prime and its reverse (96860581) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18506869 - 2⁵ = 18506837 is a prime.

It is a super-2 number, since 2×18506869² = 685008400366322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18506849) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9253434 + 9253435.

It is an arithmetic number, because the mean of its divisors is an integer number (9253435).

Almost surely, 2^18506869 is an apocalyptic number.

It is an amenable number.

18506869 is a deficient number, since it is larger than the sum of its proper divisors (1).

18506869 is an equidigital number, since it uses as much as digits as its factorization.

18506869 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 103680, while the sum is 43.

The square root of 18506869 is about 4301.9610644449. The cubic root of 18506869 is about 264.5113529837.

The spelling of 18506869 in words is "eighteen million, five hundred six thousand, eight hundred sixty-nine".