18691427 has 2 divisors, whose sum is σ = 18691428. Its totient is φ = 18691426.

The previous prime is 18691423. The next prime is 18691441. The reversal of 18691427 is 72419681.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18691427 - 2² = 18691423 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18691423) 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, 9345713 + 9345714.

It is an arithmetic number, because the mean of its divisors is an integer number (9345714).

Almost surely, 2^18691427 is an apocalyptic number.

18691427 is a deficient number, since it is larger than the sum of its proper divisors (1).

18691427 is an equidigital number, since it uses as much as digits as its factorization.

18691427 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 24192, while the sum is 38.

The square root of 18691427 is about 4323.3583011358. The cubic root of 18691427 is about 265.3877177326.

The spelling of 18691427 in words is "eighteen million, six hundred ninety-one thousand, four hundred twenty-seven".