644667043465 has 8 divisors (see below), whose sum is σ = 773605173888. Its totient is φ = 515730486960.

The previous prime is 644667043463. The next prime is 644667043487. The reversal of 644667043465 is 564340766446.

It is a happy number.

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

It is not a de Polignac number, because 644667043465 - 2¹ = 644667043463 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (644667043463) 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, 885664 + ... + 1440046.

It is an arithmetic number, because the mean of its divisors is an integer number (96700646736).

Almost surely, 2^644667043465 is an apocalyptic number.

It is an amenable number.

644667043465 is a deficient number, since it is larger than the sum of its proper divisors (128938130423).

644667043465 is a wasteful number, since it uses less digits than its factorization.

644667043465 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 786959.

The product of its (nonzero) digits is 34836480, while the sum is 55.

The spelling of 644667043465 in words is "six hundred forty-four billion, six hundred sixty-seven million, forty-three thousand, four hundred sixty-five".