645441 has 8 divisors (see below), whose sum is σ = 874944. Its totient is φ = 423120.

The previous prime is 645433. The next prime is 645443. The reversal of 645441 is 144546.

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

It is not a de Polignac number, because 645441 - 2³ = 645433 is a prime.

It is not an unprimeable number, because it can be changed into a prime (645443) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1581 + ... + 1946.

It is an arithmetic number, because the mean of its divisors is an integer number (109368).

2⁶⁴⁵⁴⁴¹ is an apocalyptic number.

645441 is a gapful number since it is divisible by the number (61) formed by its first and last digit.

It is an amenable number.

645441 is a deficient number, since it is larger than the sum of its proper divisors (229503).

645441 is a wasteful number, since it uses less digits than its factorization.

645441 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3591.

The product of its digits is 1920, while the sum is 24.

The square root of 645441 is about 803.3934279044. The cubic root of 645441 is about 86.4209129332.

Adding to 645441 its reverse (144546), we get a palindrome (789987).

The spelling of 645441 in words is "six hundred forty-five thousand, four hundred forty-one".