644355116110513 has 4 divisors (see below), whose sum is σ = 647728703106048. Its totient is φ = 640981529114980.

The previous prime is 644355116110507. The next prime is 644355116110553. The reversal of 644355116110513 is 315011611553446.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 644355116110513 - 2⁹ = 644355116110001 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (644355116110553) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1686793497481 + ... + 1686793497862.

It is an arithmetic number, because the mean of its divisors is an integer number (161932175776512).

Almost surely, 2^{644355116110513} is an apocalyptic number.

It is an amenable number.

644355116110513 is a deficient number, since it is larger than the sum of its proper divisors (3373586995535).

644355116110513 is a wasteful number, since it uses less digits than its factorization.

644355116110513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3373586995534.

The product of its (nonzero) digits is 648000, while the sum is 46.

Adding to 644355116110513 its reverse (315011611553446), we get a palindrome (959366727663959).

The spelling of 644355116110513 in words is "six hundred forty-four trillion, three hundred fifty-five billion, one hundred sixteen million, one hundred ten thousand, five hundred thirteen".