643874 has 32 divisors (see below), whose sum is σ = 1247616. Its totient is φ = 241920.

The previous prime is 643873. The next prime is 643879. The reversal of 643874 is 478346.

It is a happy number.

It is a super-3 number, since 3×643874³ = 800799733387294872, which contains 333 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 643874.

It is not an unprimeable number, because it can be changed into a prime (643873) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5642 + ... + 5754.

It is an arithmetic number, because the mean of its divisors is an integer number (38988).

2⁶⁴³⁸⁷⁴ is an apocalyptic number.

643874 is a deficient number, since it is larger than the sum of its proper divisors (603742).

643874 is a wasteful number, since it uses less digits than its factorization.

643874 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 170.

The product of its digits is 16128, while the sum is 32.

The square root of 643874 is about 802.4175970154. The cubic root of 643874 is about 86.3509187687.

The spelling of 643874 in words is "six hundred forty-three thousand, eight hundred seventy-four".