18826781 has 2 divisors, whose sum is σ = 18826782. Its totient is φ = 18826780.

The previous prime is 18826741. The next prime is 18826783. The reversal of 18826781 is 18762881.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14182756 + 4644025 = 3766^2 + 2155^2 .

It is a cyclic number.

It is not a de Polignac number, because 18826781 - 2¹⁰ = 18825757 is a prime.

It is a super-2 number, since 2×18826781² = 708895365643922, which contains 22 as substring.

Together with 18826783, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18826783) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9413390 + 9413391.

It is an arithmetic number, because the mean of its divisors is an integer number (9413391).

Almost surely, 2^18826781 is an apocalyptic number.

It is an amenable number.

18826781 is a deficient number, since it is larger than the sum of its proper divisors (1).

18826781 is an equidigital number, since it uses as much as digits as its factorization.

18826781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 43008, while the sum is 41.

The square root of 18826781 is about 4338.9838672205. The cubic root of 18826781 is about 266.0267794849.

The spelling of 18826781 in words is "eighteen million, eight hundred twenty-six thousand, seven hundred eighty-one".