208668642 has 64 divisors (see below), whose sum is σ = 543884544. Its totient is φ = 51793920.

The previous prime is 208668623. The next prime is 208668643. The reversal of 208668642 is 246866802.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a junction number, because it is equal to n+sod(n) for n = 208668594 and 208668603.

It is not an unprimeable number, because it can be changed into a prime (208668643) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1959 + ... + 20522.

It is an arithmetic number, because the mean of its divisors is an integer number (8498196).

Almost surely, 2^208668642 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 208668642, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (271942272).

208668642 is an abundant number, since it is smaller than the sum of its proper divisors (335215902).

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

208668642 is a wasteful number, since it uses less digits than its factorization.

208668642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22523.

The product of its (nonzero) digits is 221184, while the sum is 42.

The square root of 208668642 is about 14445.3674927293. The cubic root of 208668642 is about 593.1334221803.

The spelling of 208668642 in words is "two hundred eight million, six hundred sixty-eight thousand, six hundred forty-two".