687397009 has 4 divisors (see below), whose sum is σ = 740273716. Its totient is φ = 634520304.

The previous prime is 687397003. The next prime is 687397013. The reversal of 687397009 is 900793786.

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

It can be written as a sum of positive squares in 2 ways, for example, as 44622400 + 642774609 = 6680^2 + 25353^2 .

It is a cyclic number.

It is not a de Polignac number, because 687397009 - 2³ = 687397001 is a prime.

It is not an unprimeable number, because it can be changed into a prime (687397001) 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, 26438334 + ... + 26438359.

It is an arithmetic number, because the mean of its divisors is an integer number (185068429).

Almost surely, 2^687397009 is an apocalyptic number.

It is an amenable number.

687397009 is a deficient number, since it is larger than the sum of its proper divisors (52876707).

687397009 is a wasteful number, since it uses less digits than its factorization.

687397009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52876706.

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

The square root of 687397009 is about 26218.2571693848. The cubic root of 687397009 is about 882.5430096178.

The spelling of 687397009 in words is "six hundred eighty-seven million, three hundred ninety-seven thousand, nine".