666526 has 8 divisors (see below), whose sum is σ = 1142640. Its totient is φ = 285648.

The previous prime is 666511. The next prime is 666527. The reversal of 666526 is 625666.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666527) by changing a digit.

666526 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23791 + ... + 23818.

It is an arithmetic number, because the mean of its divisors is an integer number (142830).

2⁶⁶⁶⁵²⁶ is an apocalyptic number.

666526 is a deficient number, since it is larger than the sum of its proper divisors (476114).

666526 is a wasteful number, since it uses less digits than its factorization.

666526 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47618.

The product of its digits is 12960, while the sum is 31.

The square root of 666526 is about 816.4104359941. The cubic root of 666526 is about 87.3519018588.

The spelling of 666526 in words is "six hundred sixty-six thousand, five hundred twenty-six".