638849701 has 6 divisors (see below), whose sum is σ = 743151750. Its totient is φ = 547585416.

The previous prime is 638849689. The next prime is 638849723. The reversal of 638849701 is 107948836.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 628705476 + 10144225 = 25074^2 + 3185^2 .

It is not a de Polignac number, because 638849701 - 2²⁵ = 605295269 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638849201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6518826 + ... + 6518923.

It is an arithmetic number, because the mean of its divisors is an integer number (123858625).

Almost surely, 2^638849701 is an apocalyptic number.

It is an amenable number.

638849701 is a deficient number, since it is larger than the sum of its proper divisors (104302049).

638849701 is a wasteful number, since it uses less digits than its factorization.

638849701 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13037763 (or 13037756 counting only the distinct ones).

The product of its (nonzero) digits is 290304, while the sum is 46.

The square root of 638849701 is about 25275.4762764226. The cubic root of 638849701 is about 861.2572655326.

The spelling of 638849701 in words is "six hundred thirty-eight million, eight hundred forty-nine thousand, seven hundred one".