6687987 has 16 divisors (see below), whose sum is σ = 9580032. Its totient is φ = 4135040.

The previous prime is 6687983. The next prime is 6688001. The reversal of 6687987 is 7897866.

It is a happy number.

It is not a de Polignac number, because 6687987 - 2² = 6687983 is a prime.

It is a super-2 number, since 2×6687987² = 89458340224338, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (51).

6687987 is a lucky number.

It is a zygodrome in base 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6687983) 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, 2698 + ... + 4544.

It is an arithmetic number, because the mean of its divisors is an integer number (598752).

Almost surely, 2^6687987 is an apocalyptic number.

6687987 is a deficient number, since it is larger than the sum of its proper divisors (2892045).

6687987 is a wasteful number, since it uses less digits than its factorization.

6687987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1938.

The product of its digits is 1016064, while the sum is 51.

The square root of 6687987 is about 2586.1142666170. The cubic root of 6687987 is about 188.4076242965.

It can be divided in two parts, 66879 and 87, that added together give a palindrome (66966).

The spelling of 6687987 in words is "six million, six hundred eighty-seven thousand, nine hundred eighty-seven".