648139 has 4 divisors (see below), whose sum is σ = 663256. Its totient is φ = 633024.

The previous prime is 648133. The next prime is 648173. The reversal of 648139 is 931846.

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

It is a cyclic number.

It is not a de Polignac number, because 648139 - 2⁵ = 648107 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 648139.

It is not an unprimeable number, because it can be changed into a prime (648133) 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, 7494 + ... + 7579.

It is an arithmetic number, because the mean of its divisors is an integer number (165814).

2⁶⁴⁸¹³⁹ is an apocalyptic number.

648139 is a deficient number, since it is larger than the sum of its proper divisors (15117).

648139 is a wasteful number, since it uses less digits than its factorization.

648139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15116.

The product of its digits is 5184, while the sum is 31.

The square root of 648139 is about 805.0708043396. The cubic root of 648139 is about 86.5411612048.

It can be divided in two parts, 648 and 139, that added together give a palindrome (787).

The spelling of 648139 in words is "six hundred forty-eight thousand, one hundred thirty-nine".