18712919 has 2 divisors, whose sum is σ = 18712920. Its totient is φ = 18712918.

The previous prime is 18712879. The next prime is 18712921. The reversal of 18712919 is 91921781.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 18712919 - 2¹⁶ = 18647383 is a prime.

It is a super-2 number, since 2×18712919² = 700346675001122, which contains 22 as substring.

Together with 18712921, 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 (18711919) 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, 9356459 + 9356460.

It is an arithmetic number, because the mean of its divisors is an integer number (9356460).

Almost surely, 2^18712919 is an apocalyptic number.

18712919 is a deficient number, since it is larger than the sum of its proper divisors (1).

18712919 is an equidigital number, since it uses as much as digits as its factorization.

18712919 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9072, while the sum is 38.

The square root of 18712919 is about 4325.8431548081. The cubic root of 18712919 is about 265.4893958641.

The spelling of 18712919 in words is "eighteen million, seven hundred twelve thousand, nine hundred nineteen".