643746 has 16 divisors (see below), whose sum is σ = 1329408. Its totient is φ = 207600.

The previous prime is 643729. The next prime is 643751. The reversal of 643746 is 647346.

It is an unprimeable number.

643746 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1545 + ... + 1916.

It is an arithmetic number, because the mean of its divisors is an integer number (83088).

2⁶⁴³⁷⁴⁶ is an apocalyptic number.

643746 is an abundant number, since it is smaller than the sum of its proper divisors (685662).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

643746 is a wasteful number, since it uses less digits than its factorization.

643746 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3497.

The product of its digits is 12096, while the sum is 30.

The square root of 643746 is about 802.3378340824. The cubic root of 643746 is about 86.3451962981.

Subtracting 643746 from its reverse (647346), we obtain a square (3600 = 60²).

The spelling of 643746 in words is "six hundred forty-three thousand, seven hundred forty-six".