687449 has 4 divisors (see below), whose sum is σ = 785664. Its totient is φ = 589236.

The previous prime is 687443. The next prime is 687457. The reversal of 687449 is 944786.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 944786 = 2 ⋅472393.

It is a cyclic number.

It is not a de Polignac number, because 687449 - 2⁴ = 687433 is a prime.

It is a super-2 number, since 2×687449² = 945172255202, which contains 22 as substring.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (687443) 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, 49097 + ... + 49110.

It is an arithmetic number, because the mean of its divisors is an integer number (196416).

2⁶⁸⁷⁴⁴⁹ is an apocalyptic number.

It is an amenable number.

687449 is a deficient number, since it is larger than the sum of its proper divisors (98215).

687449 is an equidigital number, since it uses as much as digits as its factorization.

687449 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 98214.

The product of its digits is 48384, while the sum is 38.

The square root of 687449 is about 829.1254428613. The cubic root of 687449 is about 88.2565259320.

The spelling of 687449 in words is "six hundred eighty-seven thousand, four hundred forty-nine".