666494440 has 32 divisors (see below), whose sum is σ = 1513637280. Its totient is φ = 264104512.

The previous prime is 666494393. The next prime is 666494441. The reversal of 666494440 is 44494666.

It is not an unprimeable number, because it can be changed into a prime (666494441) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 73582 + ... + 82141.

It is an arithmetic number, because the mean of its divisors is an integer number (47301165).

Almost surely, 2^666494440 is an apocalyptic number.

It is an amenable number.

666494440 is an abundant number, since it is smaller than the sum of its proper divisors (847142840).

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

666494440 is a wasteful number, since it uses less digits than its factorization.

666494440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155841 (or 155837 counting only the distinct ones).

The product of its (nonzero) digits is 497664, while the sum is 43.

The square root of 666494440 is about 25816.5536042284. The cubic root of 666494440 is about 873.5052313316.

The spelling of 666494440 in words is "six hundred sixty-six million, four hundred ninety-four thousand, four hundred forty".