638611297 has 4 divisors (see below), whose sum is σ = 638672580. Its totient is φ = 638550016.

The previous prime is 638611279. The next prime is 638611313. The reversal of 638611297 is 792116836.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 360088576 + 278522721 = 18976^2 + 16689^2 .

It is a cyclic number.

It is not a de Polignac number, because 638611297 - 2¹¹ = 638609249 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (638611247) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10672 + ... + 37297.

It is an arithmetic number, because the mean of its divisors is an integer number (159668145).

Almost surely, 2^638611297 is an apocalyptic number.

It is an amenable number.

638611297 is a deficient number, since it is larger than the sum of its proper divisors (61283).

638611297 is a wasteful number, since it uses less digits than its factorization.

638611297 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61282.

The product of its digits is 108864, while the sum is 43.

The square root of 638611297 is about 25270.7597234432. The cubic root of 638611297 is about 861.1501184090.

The spelling of 638611297 in words is "six hundred thirty-eight million, six hundred eleven thousand, two hundred ninety-seven".