18351666637 has 2 divisors, whose sum is σ = 18351666638. Its totient is φ = 18351666636.

The previous prime is 18351666607. The next prime is 18351666653. The reversal of 18351666637 is 73666615381.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14404560361 + 3947106276 = 120019^2 + 62826^2 .

It is an emirp because it is prime and its reverse (73666615381) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18351666637 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18351666607) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9175833318 + 9175833319.

It is an arithmetic number, because the mean of its divisors is an integer number (9175833319).

Almost surely, 2^18351666637 is an apocalyptic number.

It is an amenable number.

18351666637 is a deficient number, since it is larger than the sum of its proper divisors (1).

18351666637 is an equidigital number, since it uses as much as digits as its factorization.

18351666637 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3265920, while the sum is 52.

The spelling of 18351666637 in words is "eighteen billion, three hundred fifty-one million, six hundred sixty-six thousand, six hundred thirty-seven".