644762274541 has 32 divisors (see below), whose sum is σ = 815796633600. Its totient is φ = 494978964480.

The previous prime is 644762274529. The next prime is 644762274589. The reversal of 644762274541 is 145472267446.

It is not a de Polignac number, because 644762274541 - 2¹⁹ = 644761750253 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 (644762274641) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2701965 + ... + 2930893.

It is an arithmetic number, because the mean of its divisors is an integer number (25493644800).

Almost surely, 2^644762274541 is an apocalyptic number.

It is an amenable number.

644762274541 is a deficient number, since it is larger than the sum of its proper divisors (171034359059).

644762274541 is a wasteful number, since it uses less digits than its factorization.

644762274541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 229489.

The product of its digits is 9031680, while the sum is 52.

The spelling of 644762274541 in words is "six hundred forty-four billion, seven hundred sixty-two million, two hundred seventy-four thousand, five hundred forty-one".