644027071 has 8 divisors (see below), whose sum is σ = 675218304. Its totient is φ = 613101720.

The previous prime is 644027063. The next prime is 644027101. The reversal of 644027071 is 170720446.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 644027071 - 2³ = 644027063 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644027471) 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, 61501 + ... + 71206.

It is an arithmetic number, because the mean of its divisors is an integer number (84402288).

Almost surely, 2^644027071 is an apocalyptic number.

644027071 is a deficient number, since it is larger than the sum of its proper divisors (31191233).

644027071 is a wasteful number, since it uses less digits than its factorization.

644027071 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 132941.

The product of its (nonzero) digits is 9408, while the sum is 31.

The square root of 644027071 is about 25377.6884487142. The cubic root of 644027071 is about 863.5776108780.

The spelling of 644027071 in words is "six hundred forty-four million, twenty-seven thousand, seventy-one".