644734253461 has 8 divisors (see below), whose sum is σ = 646538890880. Its totient is φ = 642929876928.

The previous prime is 644734253447. The next prime is 644734253467. The reversal of 644734253461 is 164352437446.

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

It is a cyclic number.

It is not a de Polignac number, because 644734253461 - 2⁷ = 644734253333 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 (644734253467) 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, 5560285 + ... + 5675053.

It is an arithmetic number, because the mean of its divisors is an integer number (80817361360).

Almost surely, 2^644734253461 is an apocalyptic number.

It is an amenable number.

644734253461 is a deficient number, since it is larger than the sum of its proper divisors (1804637419).

644734253461 is a wasteful number, since it uses less digits than its factorization.

644734253461 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130443.

The product of its digits is 5806080, while the sum is 49.

The spelling of 644734253461 in words is "six hundred forty-four billion, seven hundred thirty-four million, two hundred fifty-three thousand, four hundred sixty-one".