639449617 has 16 divisors (see below), whose sum is σ = 709632000. Its totient is φ = 573754320.

The previous prime is 639449599. The next prime is 639449633. The reversal of 639449617 is 716944936.

It is a cyclic number.

It is not a de Polignac number, because 639449617 - 2¹⁵ = 639416849 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (639449117) 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 15 ways as a sum of consecutive naturals, for example, 16134 + ... + 39232.

It is an arithmetic number, because the mean of its divisors is an integer number (44352000).

Almost surely, 2^639449617 is an apocalyptic number.

It is an amenable number.

639449617 is a deficient number, since it is larger than the sum of its proper divisors (70182383).

639449617 is a wasteful number, since it uses less digits than its factorization.

639449617 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23196.

The product of its digits is 979776, while the sum is 49.

The square root of 639449617 is about 25287.3410425058. The cubic root of 639449617 is about 861.5267709504.

The spelling of 639449617 in words is "six hundred thirty-nine million, four hundred forty-nine thousand, six hundred seventeen".