668676918 has 128 divisors (see below), whose sum is σ = 1774080000. Its totient is φ = 163078272.

The previous prime is 668676917. The next prime is 668676989. The reversal of 668676918 is 819676866.

It is a Harshad number since it is a multiple of its sum of digits (57).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668676917) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 445333 + ... + 446831.

It is an arithmetic number, because the mean of its divisors is an integer number (13860000).

Almost surely, 2^668676918 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 668676918, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (887040000).

668676918 is an abundant number, since it is smaller than the sum of its proper divisors (1105403082).

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

668676918 is a wasteful number, since it uses less digits than its factorization.

668676918 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1586.

The product of its digits is 5225472, while the sum is 57.

The square root of 668676918 is about 25858.7880226433. The cubic root of 668676918 is about 874.4576418000.

The spelling of 668676918 in words is "six hundred sixty-eight million, six hundred seventy-six thousand, nine hundred eighteen".