645518 has 8 divisors (see below), whose sum is σ = 1010448. Its totient is φ = 308704.

The previous prime is 645503. The next prime is 645521. The reversal of 645518 is 815546.

It is a happy number.

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

It is a congruent number.

It is an unprimeable number.

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, 6971 + ... + 7062.

It is an arithmetic number, because the mean of its divisors is an integer number (126306).

2⁶⁴⁵⁵¹⁸ is an apocalyptic number.

645518 is a deficient number, since it is larger than the sum of its proper divisors (364930).

645518 is a wasteful number, since it uses less digits than its factorization.

645518 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14058.

The product of its digits is 4800, while the sum is 29.

The square root of 645518 is about 803.4413482016. The cubic root of 645518 is about 86.4243494186.

The spelling of 645518 in words is "six hundred forty-five thousand, five hundred eighteen".