208406938866 has 96 divisors (see below), whose sum is σ = 513868110912. Its totient is φ = 55989642240.

The previous prime is 208406938847. The next prime is 208406938867. The reversal of 208406938866 is 668839604802.

It is a super-2 number, since 2×208406938866² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (208406938867) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 5463801 + ... + 5501811.

It is an arithmetic number, because the mean of its divisors is an integer number (5352792822).

Almost surely, 2^208406938866 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 208406938866, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (256934055456).

208406938866 is an abundant number, since it is smaller than the sum of its proper divisors (305461172046).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

208406938866 is a wasteful number, since it uses less digits than its factorization.

208406938866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39144 (or 39137 counting only the distinct ones).

The product of its (nonzero) digits is 23887872, while the sum is 60.

The spelling of 208406938866 in words is "two hundred eight billion, four hundred six million, nine hundred thirty-eight thousand, eight hundred sixty-six".