208839861 has 6 divisors (see below), whose sum is σ = 301657590. Its totient is φ = 139226568.

The previous prime is 208839857. The next prime is 208839893. The reversal of 208839861 is 168938802.

208839861 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 only one way, i.e., 187964100 + 20875761 = 13710^2 + 4569^2 .

It is not a de Polignac number, because 208839861 - 2² = 208839857 is a prime.

It is a super-2 number, since 2×208839861² = 87228175084998642, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (208839161) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 11602206 + ... + 11602223.

It is an arithmetic number, because the mean of its divisors is an integer number (50276265).

Almost surely, 2^208839861 is an apocalyptic number.

It is an amenable number.

208839861 is a deficient number, since it is larger than the sum of its proper divisors (92817729).

208839861 is a wasteful number, since it uses less digits than its factorization.

208839861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23204435 (or 23204432 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 45.

The square root of 208839861 is about 14451.2927103426. The cubic root of 208839861 is about 593.2956058647.

The spelling of 208839861 in words is "two hundred eight million, eight hundred thirty-nine thousand, eight hundred sixty-one".