644027070 has 64 divisors (see below), whose sum is σ = 1614712320. Its totient is φ = 164185728.

The previous prime is 644027063. The next prime is 644027101. The reversal of 644027070 is 70720446.

644027070 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 86017 + ... + 93203.

It is an arithmetic number, because the mean of its divisors is an integer number (25229880).

Almost surely, 2^644027070 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 644027070, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (807356160).

644027070 is an abundant number, since it is smaller than the sum of its proper divisors (970685250).

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

644027070 is a wasteful number, since it uses less digits than its factorization.

644027070 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7329.

The product of its (nonzero) digits is 9408, while the sum is 30.

The square root of 644027070 is about 25377.6884290118. The cubic root of 644027070 is about 863.5776104310.

The spelling of 644027070 in words is "six hundred forty-four million, twenty-seven thousand, seventy".