666578568 has 64 divisors (see below), whose sum is σ = 1782768960. Its totient is φ = 206954496.

The previous prime is 666578567. The next prime is 666578573. The reversal of 666578568 is 865875666.

It is not an unprimeable number, because it can be changed into a prime (666578567) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 31155 + ... + 47997.

It is an arithmetic number, because the mean of its divisors is an integer number (27855765).

Almost surely, 2^666578568 is an apocalyptic number.

666578568 is a gapful number since it is divisible by the number (68) 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 666578568, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (891384480).

666578568 is an abundant number, since it is smaller than the sum of its proper divisors (1116190392).

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

666578568 is a wasteful number, since it uses less digits than its factorization.

666578568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16966 (or 16962 counting only the distinct ones).

The product of its digits is 14515200, while the sum is 57.

The square root of 666578568 is about 25818.1828950064. The cubic root of 666578568 is about 873.5419824040.

The spelling of 666578568 in words is "six hundred sixty-six million, five hundred seventy-eight thousand, five hundred sixty-eight".