666522 has 16 divisors (see below), whose sum is σ = 1481280. Its totient is φ = 222156.

The previous prime is 666511. The next prime is 666527. The reversal of 666522 is 225666.

666522 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a nialpdrome in base 10.

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

666522 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6118 + ... + 6225.

It is an arithmetic number, because the mean of its divisors is an integer number (92580).

2⁶⁶⁶⁵²² is an apocalyptic number.

666522 is an abundant number, since it is smaller than the sum of its proper divisors (814758).

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

666522 is a wasteful number, since it uses less digits than its factorization.

666522 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12354 (or 12348 counting only the distinct ones).

The product of its digits is 4320, while the sum is 27.

The square root of 666522 is about 816.4079862422. The cubic root of 666522 is about 87.3517271178.

The spelling of 666522 in words is "six hundred sixty-six thousand, five hundred twenty-two".