6397987 has 4 divisors (see below), whose sum is σ = 6414040. Its totient is φ = 6381936.

The previous prime is 6397981. The next prime is 6397991. The reversal of 6397987 is 7897936.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6397987 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 6397987.

It is not an unprimeable number, because it can be changed into a prime (6397981) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7413 + ... + 8230.

It is an arithmetic number, because the mean of its divisors is an integer number (1603510).

Almost surely, 2^6397987 is an apocalyptic number.

6397987 is a deficient number, since it is larger than the sum of its proper divisors (16053).

6397987 is a wasteful number, since it uses less digits than its factorization.

6397987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16052.

The product of its digits is 571536, while the sum is 49.

The square root of 6397987 is about 2529.4242427873. The cubic root of 6397987 is about 185.6440856401.

The spelling of 6397987 in words is "six million, three hundred ninety-seven thousand, nine hundred eighty-seven".