18031919 has 2 divisors, whose sum is σ = 18031920. Its totient is φ = 18031918.

The previous prime is 18031907. The next prime is 18031933. The reversal of 18031919 is 91913081.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18031919 - 2⁴ = 18031903 is a prime.

It is a super-2 number, since 2×18031919² = 650300205645122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18031619) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9015959 + 9015960.

It is an arithmetic number, because the mean of its divisors is an integer number (9015960).

Almost surely, 2^18031919 is an apocalyptic number.

18031919 is a deficient number, since it is larger than the sum of its proper divisors (1).

18031919 is an equidigital number, since it uses as much as digits as its factorization.

18031919 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1944, while the sum is 32.

The square root of 18031919 is about 4246.4007111906. The cubic root of 18031919 is about 262.2289580273.

The spelling of 18031919 in words is "eighteen million, thirty-one thousand, nine hundred nineteen".