639113264749 has 4 divisors (see below), whose sum is σ = 642424732636. Its totient is φ = 635801796864.

The previous prime is 639113264707. The next prime is 639113264753. The reversal of 639113264749 is 947462311936.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 213804512100 + 425308752649 = 462390^2 + 652157^2 .

It is a cyclic number.

It is not a de Polignac number, because 639113264749 - 2²⁵ = 639079710317 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 639113264749.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639113264849) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1655733654 + ... + 1655734039.

It is an arithmetic number, because the mean of its divisors is an integer number (160606183159).

Almost surely, 2^639113264749 is an apocalyptic number.

It is an amenable number.

639113264749 is a deficient number, since it is larger than the sum of its proper divisors (3311467887).

639113264749 is a wasteful number, since it uses less digits than its factorization.

639113264749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3311467886.

The product of its digits is 5878656, while the sum is 55.

The spelling of 639113264749 in words is "six hundred thirty-nine billion, one hundred thirteen million, two hundred sixty-four thousand, seven hundred forty-nine".