18934781 has 2 divisors, whose sum is σ = 18934782. Its totient is φ = 18934780.

The previous prime is 18934757. The next prime is 18934793. The reversal of 18934781 is 18743981.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12888100 + 6046681 = 3590^2 + 2459^2 .

It is a cyclic number.

It is not a de Polignac number, because 18934781 - 2¹⁸ = 18672637 is a prime.

It is a super-2 number, since 2×18934781² = 717051863035922, 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 (18934081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9467390 + 9467391.

It is an arithmetic number, because the mean of its divisors is an integer number (9467391).

Almost surely, 2^18934781 is an apocalyptic number.

It is an amenable number.

18934781 is a deficient number, since it is larger than the sum of its proper divisors (1).

18934781 is an equidigital number, since it uses as much as digits as its factorization.

18934781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 48384, while the sum is 41.

The square root of 18934781 is about 4351.4113802306. The cubic root of 18934781 is about 266.5344982192.

The spelling of 18934781 in words is "eighteen million, nine hundred thirty-four thousand, seven hundred eighty-one".