668196864 has 280 divisors, whose sum is σ = 2140930440. Its totient is φ = 207028224.

The previous prime is 668196853. The next prime is 668196871. The reversal of 668196864 is 468691866.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 668196864.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 12607462 + ... + 12607514.

Almost surely, 2^668196864 is an apocalyptic number.

668196864 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 668196864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1070465220).

668196864 is an abundant number, since it is smaller than the sum of its proper divisors (1472733576).

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

668196864 is an equidigital number, since it uses as much as digits as its factorization.

668196864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110 (or 77 counting only the distinct ones).

The product of its digits is 2985984, while the sum is 54.

The square root of 668196864 is about 25849.5041345090. The cubic root of 668196864 is about 874.2483292632.

The spelling of 668196864 in words is "six hundred sixty-eight million, one hundred ninety-six thousand, eight hundred sixty-four".