638907085 has 8 divisors (see below), whose sum is σ = 773474040. Its totient is φ = 506601984.

The previous prime is 638907067. The next prime is 638907089. The reversal of 638907085 is 580709836.

638907085 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 27185796 + 611721289 = 5214^2 + 24733^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 638907085 - 2¹³ = 638898893 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638907089) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 564840 + ... + 565969.

It is an arithmetic number, because the mean of its divisors is an integer number (96684255).

Almost surely, 2^638907085 is an apocalyptic number.

It is an amenable number.

638907085 is a deficient number, since it is larger than the sum of its proper divisors (134566955).

638907085 is a wasteful number, since it uses less digits than its factorization.

638907085 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1130927.

The product of its (nonzero) digits is 362880, while the sum is 46.

The square root of 638907085 is about 25276.6114224197. The cubic root of 638907085 is about 861.2830519354.

The spelling of 638907085 in words is "six hundred thirty-eight million, nine hundred seven thousand, eighty-five".