687148009 has 2 divisors, whose sum is σ = 687148010. Its totient is φ = 687148008.

The previous prime is 687147997. The next prime is 687148019. The reversal of 687148009 is 900841786.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 484000000 + 203148009 = 22000^2 + 14253^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-687148009 is a prime.

It is not a weakly prime, because it can be changed into another prime (687148019) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343574004 + 343574005.

It is an arithmetic number, because the mean of its divisors is an integer number (343574005).

Almost surely, 2^687148009 is an apocalyptic number.

It is an amenable number.

687148009 is a deficient number, since it is larger than the sum of its proper divisors (1).

687148009 is an equidigital number, since it uses as much as digits as its factorization.

687148009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 96768, while the sum is 43.

The square root of 687148009 is about 26213.5081398885. The cubic root of 687148009 is about 882.4364337740.

The spelling of 687148009 in words is "six hundred eighty-seven million, one hundred forty-eight thousand, nine".