18774881 has 2 divisors, whose sum is σ = 18774882. Its totient is φ = 18774880.

The previous prime is 18774863. The next prime is 18774893. The reversal of 18774881 is 18847781.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12816400 + 5958481 = 3580^2 + 2441^2 .

It is a cyclic number.

It is not a de Polignac number, because 18774881 - 2¹⁰ = 18773857 is a prime.

It is a super-2 number, since 2×18774881² = 704992313128322, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18774841) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9387440 + 9387441.

It is an arithmetic number, because the mean of its divisors is an integer number (9387441).

Almost surely, 2^18774881 is an apocalyptic number.

It is an amenable number.

18774881 is a deficient number, since it is larger than the sum of its proper divisors (1).

18774881 is an equidigital number, since it uses as much as digits as its factorization.

18774881 is an evil number, because the sum of its binary digits is even.

The product of its digits is 100352, while the sum is 44.

The square root of 18774881 is about 4332.9990768520. Note that the first 3 decimals coincide. The cubic root of 18774881 is about 265.7821015014.

Subtracting 18774881 from its reverse (18847781), we obtain a square (72900 = 270²).

The spelling of 18774881 in words is "eighteen million, seven hundred seventy-four thousand, eight hundred eighty-one".