639596249 has 2 divisors, whose sum is σ = 639596250. Its totient is φ = 639596248.

The previous prime is 639596239. The next prime is 639596263. The reversal of 639596249 is 942695936.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 507691024 + 131905225 = 22532^2 + 11485^2 .

It is a cyclic number.

It is not a de Polignac number, because 639596249 - 2¹² = 639592153 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 639596249.

It is not a weakly prime, because it can be changed into another prime (639596239) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319798124 + 319798125.

It is an arithmetic number, because the mean of its divisors is an integer number (319798125).

Almost surely, 2^639596249 is an apocalyptic number.

It is an amenable number.

639596249 is a deficient number, since it is larger than the sum of its proper divisors (1).

639596249 is an equidigital number, since it uses as much as digits as its factorization.

639596249 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3149280, while the sum is 53.

The square root of 639596249 is about 25290.2401926119. The cubic root of 639596249 is about 861.5926180661.

The spelling of 639596249 in words is "six hundred thirty-nine million, five hundred ninety-six thousand, two hundred forty-nine".