649031639 has 4 divisors (see below), whose sum is σ = 652918224. Its totient is φ = 645145056.

The previous prime is 649031623. The next prime is 649031651. The reversal of 649031639 is 936130946.

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 649031639 - 2⁴ = 649031623 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 649031596 and 649031605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (649031839) 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, 1943042 + ... + 1943375.

It is an arithmetic number, because the mean of its divisors is an integer number (163229556).

Almost surely, 2^649031639 is an apocalyptic number.

649031639 is a deficient number, since it is larger than the sum of its proper divisors (3886585).

649031639 is a wasteful number, since it uses less digits than its factorization.

649031639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3886584.

The product of its (nonzero) digits is 104976, while the sum is 41.

The square root of 649031639 is about 25476.0993678389. The cubic root of 649031639 is about 865.8087212016.

The spelling of 649031639 in words is "six hundred forty-nine million, thirty-one thousand, six hundred thirty-nine".