639762247 has 8 divisors (see below), whose sum is σ = 645013376. Its totient is φ = 634532832.

The previous prime is 639762223. The next prime is 639762287. The reversal of 639762247 is 742267936.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 639762247 - 2¹⁹ = 639237959 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 639762197 and 639762206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639762287) 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 7 ways as a sum of consecutive naturals, for example, 56593 + ... + 66949.

It is an arithmetic number, because the mean of its divisors is an integer number (80626672).

Almost surely, 2^639762247 is an apocalyptic number.

639762247 is a deficient number, since it is larger than the sum of its proper divisors (5251129).

639762247 is a wasteful number, since it uses less digits than its factorization.

639762247 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10857.

The product of its digits is 762048, while the sum is 46.

The square root of 639762247 is about 25293.5218386052. The cubic root of 639762247 is about 861.6671496060.

It can be divided in two parts, 6397 and 62247, that added together give a square (68644 = 262²).

The spelling of 639762247 in words is "six hundred thirty-nine million, seven hundred sixty-two thousand, two hundred forty-seven".