644135440341 has 8 divisors (see below), whose sum is σ = 858920825664. Its totient is φ = 429386840960.

The previous prime is 644135440337. The next prime is 644135440381. The reversal of 644135440341 is 143044531446.

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 644135440341 - 2² = 644135440337 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 644135440341.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644135440381) 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, 9155601 + ... + 9225686.

It is an arithmetic number, because the mean of its divisors is an integer number (107365103208).

Almost surely, 2^644135440341 is an apocalyptic number.

It is an amenable number.

644135440341 is a deficient number, since it is larger than the sum of its proper divisors (214785385323).

644135440341 is a wasteful number, since it uses less digits than its factorization.

644135440341 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18392971.

The product of its (nonzero) digits is 276480, while the sum is 39.

Adding to 644135440341 its reverse (143044531446), we get a palindrome (787179971787).

The spelling of 644135440341 in words is "six hundred forty-four billion, one hundred thirty-five million, four hundred forty thousand, three hundred forty-one".