645743 has 8 divisors (see below), whose sum is σ = 763680. Its totient is φ = 534240.

The previous prime is 645739. The next prime is 645751. The reversal of 645743 is 347546.

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

It is not a de Polignac number, because 645743 - 2² = 645739 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645703) 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 7 ways as a sum of consecutive naturals, for example, 1388 + ... + 1793.

It is an arithmetic number, because the mean of its divisors is an integer number (95460).

2⁶⁴⁵⁷⁴³ is an apocalyptic number.

645743 is a deficient number, since it is larger than the sum of its proper divisors (117937).

645743 is a wasteful number, since it uses less digits than its factorization.

645743 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3217.

The product of its digits is 10080, while the sum is 29.

The square root of 645743 is about 803.5813586688. The cubic root of 645743 is about 86.4343895310.

The spelling of 645743 in words is "six hundred forty-five thousand, seven hundred forty-three".