18775919 has 2 divisors, whose sum is σ = 18775920. Its totient is φ = 18775918.

The previous prime is 18775903. The next prime is 18775921. The reversal of 18775919 is 91957781.

It is a strong prime.

It is an emirp because it is prime and its reverse (91957781) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18775919 - 2⁴ = 18775903 is a prime.

It is a super-2 number, since 2×18775919² = 705070268589122, which contains 22 as substring.

Together with 18775921, 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 (18775969) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9387959 + 9387960.

It is an arithmetic number, because the mean of its divisors is an integer number (9387960).

Almost surely, 2^18775919 is an apocalyptic number.

18775919 is a deficient number, since it is larger than the sum of its proper divisors (1).

18775919 is an equidigital number, since it uses as much as digits as its factorization.

18775919 is an evil number, because the sum of its binary digits is even.

The product of its digits is 158760, while the sum is 47.

The square root of 18775919 is about 4333.1188536665. The cubic root of 18775919 is about 265.7869994772.

The spelling of 18775919 in words is "eighteen million, seven hundred seventy-five thousand, nine hundred nineteen".