645123316 has 12 divisors (see below), whose sum is σ = 1152986688. Its totient is φ = 315698552.

The previous prime is 645123313. The next prime is 645123317. The reversal of 645123316 is 613321546.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645123313) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1715566 + ... + 1715941.

It is an arithmetic number, because the mean of its divisors is an integer number (96082224).

Almost surely, 2^645123316 is an apocalyptic number.

It is an amenable number.

645123316 is a deficient number, since it is larger than the sum of its proper divisors (507863372).

645123316 is a wasteful number, since it uses less digits than its factorization.

645123316 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3431558 (or 3431556 counting only the distinct ones).

The product of its digits is 12960, while the sum is 31.

The square root of 645123316 is about 25399.2778637504. The cubic root of 645123316 is about 864.0673190716.

The spelling of 645123316 in words is "six hundred forty-five million, one hundred twenty-three thousand, three hundred sixteen".