687716987 has 4 divisors (see below), whose sum is σ = 687784536. Its totient is φ = 687649440.

The previous prime is 687716977. The next prime is 687717007. The reversal of 687716987 is 789617786.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 687716987 - 2¹⁴ = 687700603 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (687716917) 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, 15038 + ... + 40019.

It is an arithmetic number, because the mean of its divisors is an integer number (171946134).

Almost surely, 2^687716987 is an apocalyptic number.

687716987 is a deficient number, since it is larger than the sum of its proper divisors (67549).

687716987 is a wasteful number, since it uses less digits than its factorization.

687716987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67548.

The product of its digits is 7112448, while the sum is 59.

The square root of 687716987 is about 26224.3586575535. The cubic root of 687716987 is about 882.6799273608.

The spelling of 687716987 in words is "six hundred eighty-seven million, seven hundred sixteen thousand, nine hundred eighty-seven".