645215275 has 6 divisors (see below), whose sum is σ = 800066972. Its totient is φ = 516172200.

The previous prime is 645215227. The next prime is 645215279. The reversal of 645215275 is 572512546.

645215275 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 645215275 - 2¹⁹ = 644690987 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645215279) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 12904281 + ... + 12904330.

Almost surely, 2^645215275 is an apocalyptic number.

645215275 is a deficient number, since it is larger than the sum of its proper divisors (154851697).

645215275 is a wasteful number, since it uses less digits than its factorization.

645215275 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25808621 (or 25808616 counting only the distinct ones).

The product of its digits is 84000, while the sum is 37.

The square root of 645215275 is about 25401.0880672463. The cubic root of 645215275 is about 864.1083732337.

It can be divided in two parts, 64521 and 5275, that added together give a palindrome (69796).

The spelling of 645215275 in words is "six hundred forty-five million, two hundred fifteen thousand, two hundred seventy-five".