641667 has 8 divisors (see below), whose sum is σ = 921424. Its totient is φ = 394848.

The previous prime is 641639. The next prime is 641681. The reversal of 641667 is 766146.

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

It is not a de Polignac number, because 641667 - 2⁸ = 641411 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (641167) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8188 + ... + 8265.

It is an arithmetic number, because the mean of its divisors is an integer number (115178).

2⁶⁴¹⁶⁶⁷ is an apocalyptic number.

641667 is a deficient number, since it is larger than the sum of its proper divisors (279757).

641667 is a wasteful number, since it uses less digits than its factorization.

641667 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16469.

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

The square root of 641667 is about 801.0411974424. The cubic root of 641667 is about 86.2521444541.

The spelling of 641667 in words is "six hundred forty-one thousand, six hundred sixty-seven".