666172 has 24 divisors (see below), whose sum is σ = 1312416. Its totient is φ = 293568.

The previous prime is 666167. The next prime is 666173. The reversal of 666172 is 271666.

It is a hoax number, since the sum of its digits (28) coincides with the sum of the digits of its distinct prime factors.

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 666172.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666173) by changing a digit.

666172 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, 918 + ... + 1474.

It is an arithmetic number, because the mean of its divisors is an integer number (54684).

2⁶⁶⁶¹⁷² is an apocalyptic number.

It is an amenable number.

666172 is a deficient number, since it is larger than the sum of its proper divisors (646244).

666172 is a wasteful number, since it uses less digits than its factorization.

666172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 597 (or 595 counting only the distinct ones).

The product of its digits is 3024, while the sum is 28.

The square root of 666172 is about 816.1936044836. The cubic root of 666172 is about 87.3364345706.

It can be divided in two parts, 666 and 172, that added together give a palindrome (838).

The spelling of 666172 in words is "six hundred sixty-six thousand, one hundred seventy-two".