644161016833 has 8 divisors (see below), whose sum is σ = 666039296160. Its totient is φ = 622576405920.

The previous prime is 644161016831. The next prime is 644161016867. The reversal of 644161016833 is 338610161446.

644161016833 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 644161016833 - 2¹ = 644161016831 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 644161016833.

It is not an unprimeable number, because it can be changed into a prime (644161016831) 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, 73412643 + ... + 73421416.

It is an arithmetic number, because the mean of its divisors is an integer number (83254912020).

Almost surely, 2^644161016833 is an apocalyptic number.

It is an amenable number.

644161016833 is a deficient number, since it is larger than the sum of its proper divisors (21878279327).

644161016833 is a wasteful number, since it uses less digits than its factorization.

644161016833 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146834207.

The product of its (nonzero) digits is 248832, while the sum is 43.

The spelling of 644161016833 in words is "six hundred forty-four billion, one hundred sixty-one million, sixteen thousand, eight hundred thirty-three".