645459 has 4 divisors (see below), whose sum is σ = 860616. Its totient is φ = 430304.

The previous prime is 645443. The next prime is 645467. The reversal of 645459 is 954546.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 645459 - 2⁴ = 645443 is a prime.

It is an Ulam number.

It is a D-number.

645459 is a lucky number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 645459.

It is not an unprimeable number, because it can be changed into a prime (645409) 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 3 ways as a sum of consecutive naturals, for example, 107574 + ... + 107579.

It is an arithmetic number, because the mean of its divisors is an integer number (215154).

2⁶⁴⁵⁴⁵⁹ is an apocalyptic number.

645459 is a deficient number, since it is larger than the sum of its proper divisors (215157).

645459 is a wasteful number, since it uses less digits than its factorization.

645459 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 215156.

The product of its digits is 21600, while the sum is 33.

The square root of 645459 is about 803.4046303078. The cubic root of 645459 is about 86.4217162919.

The spelling of 645459 in words is "six hundred forty-five thousand, four hundred fifty-nine".