644755969557446 has 8 divisors (see below), whose sum is σ = 985381764795504. Its totient is φ = 316295381292280.

The previous prime is 644755969557443. The next prime is 644755969557451.

644755969557446 is nontrivially palindromic in base 10.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644755969557443) 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, 3041301743090 + ... + 3041301743301.

It is an arithmetic number, because the mean of its divisors is an integer number (123172720599438).

Almost surely, 2^{644755969557446} is an apocalyptic number.

644755969557446 is a deficient number, since it is larger than the sum of its proper divisors (340625795238058).

644755969557446 is a wasteful number, since it uses less digits than its factorization.

644755969557446 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6082603486446.

The product of its digits is 137168640000, while the sum is 86.

The spelling of 644755969557446 in words is "six hundred forty-four trillion, seven hundred fifty-five billion, nine hundred sixty-nine million, five hundred fifty-seven thousand, four hundred forty-six".