667641 has 32 divisors (see below), whose sum is σ = 1088640. Its totient is φ = 359424.

The previous prime is 667631. The next prime is 667643. The reversal of 667641 is 146766.

It is not a de Polignac number, because 667641 - 2⁶ = 667577 is a prime.

667641 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 667599 and 667608.

It is not an unprimeable number, because it can be changed into a prime (667643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 12571 + ... + 12623.

It is an arithmetic number, because the mean of its divisors is an integer number (34020).

2⁶⁶⁷⁶⁴¹ is an apocalyptic number.

It is an amenable number.

667641 is a deficient number, since it is larger than the sum of its proper divisors (420999).

667641 is a wasteful number, since it uses less digits than its factorization.

667641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105.

The product of its digits is 6048, while the sum is 30.

The square root of 667641 is about 817.0930179606. The cubic root of 667641 is about 87.4005836860.

The spelling of 667641 in words is "six hundred sixty-seven thousand, six hundred forty-one".