18934381 has 2 divisors, whose sum is σ = 18934382. Its totient is φ = 18934380.

The previous prime is 18934367. The next prime is 18934423. The reversal of 18934381 is 18343981.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18922500 + 11881 = 4350^2 + 109^2 .

It is a cyclic number.

It is not a de Polignac number, because 18934381 - 2¹⁵ = 18901613 is a prime.

It is a super-2 number, since 2×18934381² = 717021567706322, 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 18934381.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18934301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9467190 + 9467191.

It is an arithmetic number, because the mean of its divisors is an integer number (9467191).

Almost surely, 2^18934381 is an apocalyptic number.

It is an amenable number.

18934381 is a deficient number, since it is larger than the sum of its proper divisors (1).

18934381 is an equidigital number, since it uses as much as digits as its factorization.

18934381 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20736, while the sum is 37.

The square root of 18934381 is about 4351.3654178890. The cubic root of 18934381 is about 266.5326213460.

The spelling of 18934381 in words is "eighteen million, nine hundred thirty-four thousand, three hundred eighty-one".