18396987897 has 16 divisors (see below), whose sum is σ = 26478426240. Its totient is φ = 11326879872.

The previous prime is 18396987883. The next prime is 18396987901. The reversal of 18396987897 is 79878969381.

It is not a de Polignac number, because 18396987897 - 2¹⁹ = 18396463609 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18396987857) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4594948 + ... + 4598949.

It is an arithmetic number, because the mean of its divisors is an integer number (1654901640).

Almost surely, 2^18396987897 is an apocalyptic number.

It is an amenable number.

18396987897 is a deficient number, since it is larger than the sum of its proper divisors (8081438343).

18396987897 is a wasteful number, since it uses less digits than its factorization.

18396987897 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9193952.

The product of its digits is 329204736, while the sum is 75.

The spelling of 18396987897 in words is "eighteen billion, three hundred ninety-six million, nine hundred eighty-seven thousand, eight hundred ninety-seven".