639829538 has 8 divisors (see below), whose sum is σ = 959861532. Its totient is φ = 319875696.

The previous prime is 639829537. The next prime is 639829573. The reversal of 639829538 is 835928936.

It can be written as a sum of positive squares in 2 ways, for example, as 580954609 + 58874929 = 24103^2 + 7673^2 .

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

It is a self number, because there is not a number n which added to its sum of digits gives 639829538.

It is not an unprimeable number, because it can be changed into a prime (639829537) 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, 9656 + ... + 37052.

Almost surely, 2^639829538 is an apocalyptic number.

639829538 is a deficient number, since it is larger than the sum of its proper divisors (320031994).

639829538 is a wasteful number, since it uses less digits than its factorization.

639829538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39076.

The product of its digits is 2799360, while the sum is 53.

The square root of 639829538 is about 25294.8520058924. The cubic root of 639829538 is about 861.6973589594.

The spelling of 639829538 in words is "six hundred thirty-nine million, eight hundred twenty-nine thousand, five hundred thirty-eight".