18501605987 has 2 divisors, whose sum is σ = 18501605988. Its totient is φ = 18501605986.

The previous prime is 18501605963. The next prime is 18501606007. The reversal of 18501605987 is 78950610581.

It is a strong prime.

It is an emirp because it is prime and its reverse (78950610581) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18501605987 - 2²² = 18497411683 is a prime.

It is not a weakly prime, because it can be changed into another prime (18501605387) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9250802993 + 9250802994.

It is an arithmetic number, because the mean of its divisors is an integer number (9250802994).

Almost surely, 2^18501605987 is an apocalyptic number.

18501605987 is a deficient number, since it is larger than the sum of its proper divisors (1).

18501605987 is an equidigital number, since it uses as much as digits as its factorization.

18501605987 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 604800, while the sum is 50.

The spelling of 18501605987 in words is "eighteen billion, five hundred one million, six hundred five thousand, nine hundred eighty-seven".