18790381 has 2 divisors, whose sum is σ = 18790382. Its totient is φ = 18790380.

The previous prime is 18790367. The next prime is 18790399. The reversal of 18790381 is 18309781.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12709225 + 6081156 = 3565^2 + 2466^2 .

It is a cyclic number.

It is not a de Polignac number, because 18790381 - 2⁵ = 18790349 is a prime.

It is a super-2 number, since 2×18790381² = 706156836250322, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 18790381.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18790361) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9395190 + 9395191.

It is an arithmetic number, because the mean of its divisors is an integer number (9395191).

Almost surely, 2^18790381 is an apocalyptic number.

It is an amenable number.

18790381 is a deficient number, since it is larger than the sum of its proper divisors (1).

18790381 is an equidigital number, since it uses as much as digits as its factorization.

18790381 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12096, while the sum is 37.

The square root of 18790381 is about 4334.7873073543. The cubic root of 18790381 is about 265.8552220610.

The spelling of 18790381 in words is "eighteen million, seven hundred ninety thousand, three hundred eighty-one".