687149 has 4 divisors (see below), whose sum is σ = 696636. Its totient is φ = 677664.

The previous prime is 687139. The next prime is 687151. The reversal of 687149 is 941786.

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 592900 + 94249 = 770^2 + 307^2 .

It is a cyclic number.

It is not a de Polignac number, because 687149 - 2⁸ = 686893 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (687109) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4634 + ... + 4779.

It is an arithmetic number, because the mean of its divisors is an integer number (174159).

2⁶⁸⁷¹⁴⁹ is an apocalyptic number.

It is an amenable number.

687149 is a deficient number, since it is larger than the sum of its proper divisors (9487).

687149 is an equidigital number, since it uses as much as digits as its factorization.

687149 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9486.

The product of its digits is 12096, while the sum is 35.

The square root of 687149 is about 828.9445096024. The cubic root of 687149 is about 88.2436857988.

The spelling of 687149 in words is "six hundred eighty-seven thousand, one hundred forty-nine".