638881213 has 8 divisors (see below), whose sum is σ = 674075520. Its totient is φ = 603843840.

The previous prime is 638881211. The next prime is 638881219. The reversal of 638881213 is 312188836.

638881213 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 638881213 - 2¹ = 638881211 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 (638881211) 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, 30820 + ... + 47197.

It is an arithmetic number, because the mean of its divisors is an integer number (84259440).

Almost surely, 2^638881213 is an apocalyptic number.

It is an amenable number.

638881213 is a deficient number, since it is larger than the sum of its proper divisors (35194307).

638881213 is a wasteful number, since it uses less digits than its factorization.

638881213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78467.

The product of its digits is 55296, while the sum is 40.

The square root of 638881213 is about 25276.0996397783. The cubic root of 638881213 is about 861.2714261365.

The spelling of 638881213 in words is "six hundred thirty-eight million, eight hundred eighty-one thousand, two hundred thirteen".