18071381 has 2 divisors, whose sum is σ = 18071382. Its totient is φ = 18071380.

The previous prime is 18071377. The next prime is 18071387. The reversal of 18071381 is 18317081.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16728100 + 1343281 = 4090^2 + 1159^2 .

It is a cyclic number.

It is not a de Polignac number, because 18071381 - 2² = 18071377 is a prime.

It is a super-2 number, since 2×18071381² = 653149622494322, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18071387) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9035690 + 9035691.

It is an arithmetic number, because the mean of its divisors is an integer number (9035691).

Almost surely, 2^18071381 is an apocalyptic number.

It is an amenable number.

18071381 is a deficient number, since it is larger than the sum of its proper divisors (1).

18071381 is an equidigital number, since it uses as much as digits as its factorization.

18071381 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1344, while the sum is 29.

The square root of 18071381 is about 4251.0446951308. The cubic root of 18071381 is about 262.4201105339.

The spelling of 18071381 in words is "eighteen million, seventy-one thousand, three hundred eighty-one".