666640260 has 384 divisors, whose sum is σ = 2489356800. Its totient is φ = 145981440.

The previous prime is 666640259. The next prime is 666640277. The reversal of 666640260 is 62046666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 6872532 + ... + 6872628.

It is an arithmetic number, because the mean of its divisors is an integer number (6482700).

Almost surely, 2^666640260 is an apocalyptic number.

666640260 is a gapful number since it is divisible by the number (60) 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 666640260, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1244678400).

666640260 is an abundant number, since it is smaller than the sum of its proper divisors (1822716540).

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

666640260 is a wasteful number, since it uses less digits than its factorization.

666640260 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 228 (or 220 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 36.

The square root of 666640260 is about 25819.3776067511. The cubic root of 666640260 is about 873.5689304099.

The spelling of 666640260 in words is "six hundred sixty-six million, six hundred forty thousand, two hundred sixty".