644088109 has 8 divisors (see below), whose sum is σ = 737130240. Its totient is φ = 551303376.

The previous prime is 644088089. The next prime is 644088121. The reversal of 644088109 is 901880446.

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 644088109 - 2⁵ = 644088077 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644088199) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 58954 + ... + 69019.

It is an arithmetic number, because the mean of its divisors is an integer number (92141280).

Almost surely, 2^644088109 is an apocalyptic number.

It is an amenable number.

644088109 is a deficient number, since it is larger than the sum of its proper divisors (93042131).

644088109 is a wasteful number, since it uses less digits than its factorization.

644088109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128699.

The product of its (nonzero) digits is 55296, while the sum is 40.

The square root of 644088109 is about 25378.8910120202. The cubic root of 644088109 is about 863.6048920216.

It can be divided in two parts, 6440 and 88109, that added together give a palindrome (94549).

The spelling of 644088109 in words is "six hundred forty-four million, eighty-eight thousand, one hundred nine".