687006509 has 6 divisors (see below), whose sum is σ = 799170894. Its totient is φ = 588862680.

The previous prime is 687006497. The next prime is 687006557. The reversal of 687006509 is 905600786.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 556818409 + 130188100 = 23597^2 + 11410^2 .

It is not a de Polignac number, because 687006509 - 2⁸ = 687006253 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (687006559) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 7010222 + ... + 7010319.

It is an arithmetic number, because the mean of its divisors is an integer number (133195149).

Almost surely, 2^687006509 is an apocalyptic number.

It is an amenable number.

687006509 is a deficient number, since it is larger than the sum of its proper divisors (112164385).

687006509 is a wasteful number, since it uses less digits than its factorization.

687006509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14020555 (or 14020548 counting only the distinct ones).

The product of its (nonzero) digits is 90720, while the sum is 41.

The square root of 687006509 is about 26210.8090107879. The cubic root of 687006509 is about 882.3758581165.

The spelling of 687006509 in words is "six hundred eighty-seven million, six thousand, five hundred nine".