643954 has 8 divisors (see below), whose sum is σ = 1008000. Its totient is φ = 307956.

The previous prime is 643949. The next prime is 643957. The reversal of 643954 is 459346.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643957) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6954 + ... + 7045.

It is an arithmetic number, because the mean of its divisors is an integer number (126000).

2⁶⁴³⁹⁵⁴ is an apocalyptic number.

643954 is a deficient number, since it is larger than the sum of its proper divisors (364046).

643954 is a wasteful number, since it uses less digits than its factorization.

643954 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14024.

The product of its digits is 12960, while the sum is 31.

The square root of 643954 is about 802.4674448225. The cubic root of 643954 is about 86.3544949277.

The spelling of 643954 in words is "six hundred forty-three thousand, nine hundred fifty-four".