645447 has 8 divisors (see below), whose sum is σ = 938880. Its totient is φ = 391160.

The previous prime is 645443. The next prime is 645467. The reversal of 645447 is 744546.

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

It is not a de Polignac number, because 645447 - 2² = 645443 is a prime.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 645447.

It is not an unprimeable number, because it can be changed into a prime (645443) 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 7 ways as a sum of consecutive naturals, for example, 9747 + ... + 9812.

It is an arithmetic number, because the mean of its divisors is an integer number (117360).

2⁶⁴⁵⁴⁴⁷ is an apocalyptic number.

645447 is a deficient number, since it is larger than the sum of its proper divisors (293433).

645447 is a wasteful number, since it uses less digits than its factorization.

645447 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19573.

The product of its digits is 13440, while the sum is 30.

The square root of 645447 is about 803.3971620562. The cubic root of 645447 is about 86.4211807211.

Subtracting 645447 from its reverse (744546), we obtain a palindrome (99099).

The spelling of 645447 in words is "six hundred forty-five thousand, four hundred forty-seven".