645222644 has 24 divisors (see below), whose sum is σ = 1232682528. Its totient is φ = 293070240.

The previous prime is 645222637. The next prime is 645222647. The reversal of 645222644 is 446222546.

645222644 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Smith number, since the sum of its digits (35) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645222647) 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, 67082 + ... + 76094.

It is an arithmetic number, because the mean of its divisors is an integer number (51361772).

Almost surely, 2^645222644 is an apocalyptic number.

It is an amenable number.

645222644 is a deficient number, since it is larger than the sum of its proper divisors (587459884).

645222644 is a wasteful number, since it uses less digits than its factorization.

645222644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10655 (or 10653 counting only the distinct ones).

The product of its digits is 92160, while the sum is 35.

The square root of 645222644 is about 25401.2331196735. The cubic root of 645222644 is about 864.1116628801. Note that the first 3 decimals are identical.

The spelling of 645222644 in words is "six hundred forty-five million, two hundred twenty-two thousand, six hundred forty-four".