641979 has 32 divisors (see below), whose sum is σ = 1075200. Its totient is φ = 375840.

The previous prime is 641969. The next prime is 641981. The reversal of 641979 is 979146.

641979 is a `hidden beast` number, since 641 + 9 + 7 + 9 = 666.

It is not a de Polignac number, because 641979 - 2⁹ = 641467 is a prime.

It is not an unprimeable number, because it can be changed into a prime (641909) 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, 10852 + ... + 10910.

It is an arithmetic number, because the mean of its divisors is an integer number (33600).

2⁶⁴¹⁹⁷⁹ is an apocalyptic number.

641979 is a deficient number, since it is larger than the sum of its proper divisors (433221).

641979 is a wasteful number, since it uses less digits than its factorization.

641979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 112 (or 106 counting only the distinct ones).

The product of its digits is 13608, while the sum is 36.

The square root of 641979 is about 801.2359203131. The cubic root of 641979 is about 86.2661217501.

The spelling of 641979 in words is "six hundred forty-one thousand, nine hundred seventy-nine".