644453070 has 16 divisors (see below), whose sum is σ = 1546687440. Its totient is φ = 171854144.

The previous prime is 644453063. The next prime is 644453071. The reversal of 644453070 is 70354446.

It is a happy number.

644453070 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644453071) 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, 10740855 + ... + 10740914.

It is an arithmetic number, because the mean of its divisors is an integer number (96667965).

Almost surely, 2^644453070 is an apocalyptic number.

644453070 is an abundant number, since it is smaller than the sum of its proper divisors (902234370).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

644453070 is a wasteful number, since it uses less digits than its factorization.

644453070 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21481779.

The product of its (nonzero) digits is 40320, while the sum is 33.

The square root of 644453070 is about 25386.0802409509. The cubic root of 644453070 is about 863.7679766414.

The spelling of 644453070 in words is "six hundred forty-four million, four hundred fifty-three thousand, seventy".