838640209 has 16 divisors (see below), whose sum is σ = 971334720. Its totient is φ = 715599360.

The previous prime is 838640207. The next prime is 838640233. The reversal of 838640209 is 902046838.

838640209 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 838640209 - 2¹ = 838640207 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (838640207) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 64957 + ... + 76789.

It is an arithmetic number, because the mean of its divisors is an integer number (60708420).

Almost surely, 2^838640209 is an apocalyptic number.

It is an amenable number.

838640209 is a deficient number, since it is larger than the sum of its proper divisors (132694511).

838640209 is a wasteful number, since it uses less digits than its factorization.

838640209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12240.

The product of its (nonzero) digits is 82944, while the sum is 40.

The square root of 838640209 is about 28959.2853675639. The cubic root of 838640209 is about 943.0293879280.

The spelling of 838640209 in words is "eight hundred thirty-eight million, six hundred forty thousand, two hundred nine".