666550040 has 32 divisors (see below), whose sum is σ = 1615103280. Its totient is φ = 246110592.

The previous prime is 666550021. The next prime is 666550069. The reversal of 666550040 is 40055666.

It is a junction number, because it is equal to n+sod(n) for n = 666549979 and 666550006.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 640394 + ... + 641433.

Almost surely, 2^666550040 is an apocalyptic number.

It is an amenable number.

666550040 is an abundant number, since it is smaller than the sum of its proper divisors (948553240).

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

666550040 is a wasteful number, since it uses less digits than its factorization.

666550040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1281851 (or 1281847 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 32.

The square root of 666550040 is about 25817.6304102449. The cubic root of 666550040 is about 873.5295203766.

The spelling of 666550040 in words is "six hundred sixty-six million, five hundred fifty thousand, forty".