643742 has 16 divisors (see below), whose sum is σ = 1090800. Its totient is φ = 282240.

The previous prime is 643729. The next prime is 643751. The reversal of 643742 is 247346.

It is a happy number.

It is a d-powerful number, because it can be written as 6² + 4² + 7⁶ + 3⁶ + 4⁵ + 2¹⁹ .

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 134 + ... + 1142.

It is an arithmetic number, because the mean of its divisors is an integer number (68175).

2⁶⁴³⁷⁴² is an apocalyptic number.

643742 is a deficient number, since it is larger than the sum of its proper divisors (447058).

643742 is a wasteful number, since it uses less digits than its factorization.

643742 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1051.

The product of its digits is 4032, while the sum is 26.

The square root of 643742 is about 802.3353413629. The cubic root of 643742 is about 86.3450174586.

The spelling of 643742 in words is "six hundred forty-three thousand, seven hundred forty-two".