645280279 has 8 divisors (see below), whose sum is σ = 738587520. Its totient is φ = 552254136.

The previous prime is 645280267. The next prime is 645280297. The reversal of 645280279 is 972082546.

645280279 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a de Polignac number, because none of the positive numbers 2^k-645280279 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645280079) 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, 65329 + ... + 74554.

It is an arithmetic number, because the mean of its divisors is an integer number (92323440).

Almost surely, 2^645280279 is an apocalyptic number.

645280279 is a deficient number, since it is larger than the sum of its proper divisors (93307241).

645280279 is a wasteful number, since it uses less digits than its factorization.

645280279 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140549.

The product of its (nonzero) digits is 241920, while the sum is 43.

The square root of 645280279 is about 25402.3675865066. The cubic root of 645280279 is about 864.1373912563.

The spelling of 645280279 in words is "six hundred forty-five million, two hundred eighty thousand, two hundred seventy-nine".