644501234324263 has 16 divisors (see below), whose sum is σ = 648635279040000. Its totient is φ = 640370508880032.

The previous prime is 644501234324249. The next prime is 644501234324293. The reversal of 644501234324263 is 362423432105446.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-644501234324263 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 (644501234324243) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4821553993 + ... + 4821687661.

It is an arithmetic number, because the mean of its divisors is an integer number (40539704940000).

Almost surely, 2^{644501234324263} is an apocalyptic number.

644501234324263 is a deficient number, since it is larger than the sum of its proper divisors (4134044715737).

644501234324263 is a wasteful number, since it uses less digits than its factorization.

644501234324263 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 145854.

The product of its (nonzero) digits is 9953280, while the sum is 49.

The spelling of 644501234324263 in words is "six hundred forty-four trillion, five hundred one billion, two hundred thirty-four million, three hundred twenty-four thousand, two hundred sixty-three".