666540006 has 32 divisors (see below), whose sum is σ = 1468682496. Its totient is φ = 199980000.

The previous prime is 666540001. The next prime is 666540011. The reversal of 666540006 is 600045666.

It is an interprime number because it is at equal distance from previous prime (666540001) and next prime (666540011).

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666540001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 43330 + ... + 56661.

It is an arithmetic number, because the mean of its divisors is an integer number (45896328).

Almost surely, 2^666540006 is an apocalyptic number.

666540006 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

666540006 is an abundant number, since it is smaller than the sum of its proper divisors (802142490).

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

666540006 is a wasteful number, since it uses less digits than its factorization.

666540006 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 100108.

The product of its (nonzero) digits is 25920, while the sum is 33.

The square root of 666540006 is about 25817.4360849407. The cubic root of 666540006 is about 873.5251370902.

The spelling of 666540006 in words is "six hundred sixty-six million, five hundred forty thousand, six".