644760973941 has 8 divisors (see below), whose sum is σ = 982492912704. Its totient is φ = 368434842240.

The previous prime is 644760973939. The next prime is 644760973949. The reversal of 644760973941 is 149379067446.

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

It is not a de Polignac number, because 644760973941 - 2¹ = 644760973939 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644760973949) 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, 15351451740 + ... + 15351451781.

It is an arithmetic number, because the mean of its divisors is an integer number (122811614088).

Almost surely, 2^644760973941 is an apocalyptic number.

It is an amenable number.

644760973941 is a deficient number, since it is larger than the sum of its proper divisors (337731938763).

644760973941 is a wasteful number, since it uses less digits than its factorization.

644760973941 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30702903531.

The product of its (nonzero) digits is 27433728, while the sum is 60.

The spelling of 644760973941 in words is "six hundred forty-four billion, seven hundred sixty million, nine hundred seventy-three thousand, nine hundred forty-one".