639850730 has 8 divisors (see below), whose sum is σ = 1151731332. Its totient is φ = 255940288.

The previous prime is 639850723. The next prime is 639850733. The reversal of 639850730 is 37058936.

It can be written as a sum of positive squares in 2 ways, for example, as 620657569 + 19193161 = 24913^2 + 4381^2 .

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

It is not an unprimeable number, because it can be changed into a prime (639850733) 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, 31992527 + ... + 31992546.

Almost surely, 2^639850730 is an apocalyptic number.

639850730 is a deficient number, since it is larger than the sum of its proper divisors (511880602).

639850730 is a wasteful number, since it uses less digits than its factorization.

639850730 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63985080.

The product of its (nonzero) digits is 136080, while the sum is 41.

The square root of 639850730 is about 25295.2709018899. The cubic root of 639850730 is about 861.7068723728.

The spelling of 639850730 in words is "six hundred thirty-nine million, eight hundred fifty thousand, seven hundred thirty".