666672 has 80 divisors (see below), whose sum is σ = 1964160. Its totient is φ = 193536.

The previous prime is 666671. The next prime is 666683. The reversal of 666672 is 276666.

Its product of digits (18144) is a multiple of the sum of its prime divisors (84).

It is not an unprimeable number, because it can be changed into a prime (666671) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15483 + ... + 15525.

It is an arithmetic number, because the mean of its divisors is an integer number (24552).

2⁶⁶⁶⁶⁷² is an apocalyptic number.

It is a pronic number, being equal to 816×817.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 666672, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (982080).

666672 is an abundant number, since it is smaller than the sum of its proper divisors (1297488).

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

666672 is a wasteful number, since it uses less digits than its factorization.

666672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90 (or 84 counting only the distinct ones).

The product of its digits is 18144, while the sum is 33.

The square root of 666672 is about 816.4998469075. The cubic root of 666672 is about 87.3582794278.

The spelling of 666672 in words is "six hundred sixty-six thousand, six hundred seventy-two".