645354644 has 24 divisors (see below), whose sum is σ = 1237487328. Its totient is φ = 292046240.

The previous prime is 645354643. The next prime is 645354649. The reversal of 645354644 is 446453546.

645354644 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645354643) 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, 22319 + ... + 42294.

It is an arithmetic number, because the mean of its divisors is an integer number (51561972).

Almost surely, 2^645354644 is an apocalyptic number.

It is an amenable number.

645354644 is a deficient number, since it is larger than the sum of its proper divisors (592132684).

645354644 is a wasteful number, since it uses less digits than its factorization.

645354644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64855 (or 64853 counting only the distinct ones).

The product of its digits is 691200, while the sum is 41.

The square root of 645354644 is about 25403.8312858514. The cubic root of 645354644 is about 864.1705856737.

The spelling of 645354644 in words is "six hundred forty-five million, three hundred fifty-four thousand, six hundred forty-four".