649131239 has 4 divisors (see below), whose sum is σ = 649303824. Its totient is φ = 648958656.

The previous prime is 649131221. The next prime is 649131253. The reversal of 649131239 is 932131946.

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 649131239 - 2²⁰ = 648082663 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (649131209) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 80522 + ... + 88215.

It is an arithmetic number, because the mean of its divisors is an integer number (162325956).

Almost surely, 2^649131239 is an apocalyptic number.

649131239 is a deficient number, since it is larger than the sum of its proper divisors (172585).

649131239 is a wasteful number, since it uses less digits than its factorization.

649131239 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 172584.

The product of its digits is 34992, while the sum is 38.

The square root of 649131239 is about 25478.0540661959. The cubic root of 649131239 is about 865.8530077626.

The spelling of 649131239 in words is "six hundred forty-nine million, one hundred thirty-one thousand, two hundred thirty-nine".