666944460 has 288 divisors, whose sum is σ = 2622197760. Its totient is φ = 133249536.

The previous prime is 666944431. The next prime is 666944461. The reversal of 666944460 is 64449666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (666944461) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 310149 + ... + 312291.

Almost surely, 2^666944460 is an apocalyptic number.

666944460 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 666944460, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1311098880).

666944460 is an abundant number, since it is smaller than the sum of its proper divisors (1955253300).

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

666944460 is a wasteful number, since it uses less digits than its factorization.

666944460 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2197 (or 2192 counting only the distinct ones).

The product of its (nonzero) digits is 746496, while the sum is 45.

The square root of 666944460 is about 25825.2678592111. The cubic root of 666944460 is about 873.7017853015.

The spelling of 666944460 in words is "six hundred sixty-six million, nine hundred forty-four thousand, four hundred sixty".