645279 has 8 divisors (see below), whose sum is σ = 890160. Its totient is φ = 415296.

The previous prime is 645257. The next prime is 645313. The reversal of 645279 is 972546.

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

It is not a de Polignac number, because 645279 - 2⁸ = 645023 is a prime.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645179) 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, 3622 + ... + 3795.

It is an arithmetic number, because the mean of its divisors is an integer number (111270).

2⁶⁴⁵²⁷⁹ is an apocalyptic number.

645279 is a deficient number, since it is larger than the sum of its proper divisors (244881).

645279 is a wasteful number, since it uses less digits than its factorization.

645279 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7449.

The product of its digits is 15120, while the sum is 33.

The square root of 645279 is about 803.2925992439. The cubic root of 645279 is about 86.4136820325.

The spelling of 645279 in words is "six hundred forty-five thousand, two hundred seventy-nine".