645916333 has 4 divisors (see below), whose sum is σ = 668189340. Its totient is φ = 623643328.

The previous prime is 645916331. The next prime is 645916339. The reversal of 645916333 is 333619546.

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

It can be written as a sum of positive squares in 2 ways, for example, as 155825289 + 490091044 = 12483^2 + 22138^2 .

It is a cyclic number.

It is not a de Polignac number, because 645916333 - 2¹ = 645916331 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 (645916331) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11136460 + ... + 11136517.

It is an arithmetic number, because the mean of its divisors is an integer number (167047335).

Almost surely, 2^645916333 is an apocalyptic number.

It is an amenable number.

645916333 is a deficient number, since it is larger than the sum of its proper divisors (22273007).

645916333 is a wasteful number, since it uses less digits than its factorization.

645916333 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22273006.

The product of its digits is 174960, while the sum is 40.

The square root of 645916333 is about 25414.8840839379. The cubic root of 645916333 is about 864.4212253090.

The spelling of 645916333 in words is "six hundred forty-five million, nine hundred sixteen thousand, three hundred thirty-three".