18695381 has 2 divisors, whose sum is σ = 18695382. Its totient is φ = 18695380.

The previous prime is 18695371. The next prime is 18695399. The reversal of 18695381 is 18359681.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12013156 + 6682225 = 3466^2 + 2585^2 .

It is a cyclic number.

It is not a de Polignac number, because 18695381 - 2⁶ = 18695317 is a prime.

It is a super-2 number, since 2×18695381² = 699034541470322, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18695311) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9347690 + 9347691.

It is an arithmetic number, because the mean of its divisors is an integer number (9347691).

Almost surely, 2^18695381 is an apocalyptic number.

It is an amenable number.

18695381 is a deficient number, since it is larger than the sum of its proper divisors (1).

18695381 is an equidigital number, since it uses as much as digits as its factorization.

18695381 is an evil number, because the sum of its binary digits is even.

The product of its digits is 51840, while the sum is 41.

The square root of 18695381 is about 4323.8155603587. The cubic root of 18695381 is about 265.4064298593.

The spelling of 18695381 in words is "eighteen million, six hundred ninety-five thousand, three hundred eighty-one".