644343440102 has 8 divisors (see below), whose sum is σ = 968499792336. Its totient is φ = 321510175992.

The previous prime is 644343440047. The next prime is 644343440123. The reversal of 644343440102 is 201044343446.

It is a happy number.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 330770813 + ... + 330772760.

It is an arithmetic number, because the mean of its divisors is an integer number (121062474042).

Almost surely, 2^644343440102 is an apocalyptic number.

644343440102 is a deficient number, since it is larger than the sum of its proper divisors (324156352234).

644343440102 is a wasteful number, since it uses less digits than its factorization.

644343440102 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 661544062.

The product of its (nonzero) digits is 110592, while the sum is 35.

Adding to 644343440102 its reverse (201044343446), we get a palindrome (845387783548).

The spelling of 644343440102 in words is "six hundred forty-four billion, three hundred forty-three million, four hundred forty thousand, one hundred two".