644141651603 has 4 divisors (see below), whose sum is σ = 646340087568. Its totient is φ = 641943215640.

The previous prime is 644141651597. The next prime is 644141651717. The reversal of 644141651603 is 306156141446.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 644141651603 - 2²⁰ = 644140603027 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (644141654603) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1099217543 + ... + 1099218128.

It is an arithmetic number, because the mean of its divisors is an integer number (161585021892).

Almost surely, 2^644141651603 is an apocalyptic number.

644141651603 is a deficient number, since it is larger than the sum of its proper divisors (2198435965).

644141651603 is a wasteful number, since it uses less digits than its factorization.

644141651603 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2198435964.

The product of its (nonzero) digits is 207360, while the sum is 41.

The spelling of 644141651603 in words is "six hundred forty-four billion, one hundred forty-one million, six hundred fifty-one thousand, six hundred three".