639734543 has 6 divisors (see below), whose sum is σ = 744181056. Its totient is φ = 548343852.

The previous prime is 639734533. The next prime is 639734549. The reversal of 639734543 is 345437936.

It is not a de Polignac number, because 639734543 - 2⁶ = 639734479 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 639734494 and 639734503.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639734549) 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 5 ways as a sum of consecutive naturals, for example, 6527855 + ... + 6527952.

It is an arithmetic number, because the mean of its divisors is an integer number (124030176).

Almost surely, 2^639734543 is an apocalyptic number.

639734543 is a deficient number, since it is larger than the sum of its proper divisors (104446513).

639734543 is a wasteful number, since it uses less digits than its factorization.

639734543 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13055821 (or 13055814 counting only the distinct ones).

The product of its digits is 816480, while the sum is 44.

The square root of 639734543 is about 25292.9741825670. The cubic root of 639734543 is about 861.6547116671.

The spelling of 639734543 in words is "six hundred thirty-nine million, seven hundred thirty-four thousand, five hundred forty-three".