867639 has 4 divisors (see below), whose sum is σ = 1156856. Its totient is φ = 578424.

The previous prime is 867631. The next prime is 867641. The reversal of 867639 is 936768.

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

It is not a de Polignac number, because 867639 - 2³ = 867631 is a prime.

It is a D-number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 867597 and 867606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (867631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 144604 + ... + 144609.

It is an arithmetic number, because the mean of its divisors is an integer number (289214).

2⁸⁶⁷⁶³⁹ is an apocalyptic number.

867639 is a deficient number, since it is larger than the sum of its proper divisors (289217).

867639 is a wasteful number, since it uses less digits than its factorization.

867639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 289216.

The product of its digits is 54432, while the sum is 39.

The square root of 867639 is about 931.4714166307. The cubic root of 867639 is about 95.3775923182.

The spelling of 867639 in words is "eight hundred sixty-seven thousand, six hundred thirty-nine".