646444444645 has 16 divisors (see below), whose sum is σ = 779729852160. Its totient is φ = 514494742464.

The previous prime is 646444444621. The next prime is 646444444699. The reversal of 646444444645 is 546444444646.

It is a cyclic number.

It is not a de Polignac number, because 646444444645 - 2⁷ = 646444444517 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1249012 + ... + 1689058.

It is an arithmetic number, because the mean of its divisors is an integer number (48733115760).

Almost surely, 2^646444444645 is an apocalyptic number.

It is an amenable number.

646444444645 is a deficient number, since it is larger than the sum of its proper divisors (133285407515).

646444444645 is a wasteful number, since it uses less digits than its factorization.

646444444645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 441564.

The product of its digits is 70778880, while the sum is 55.

Subtracting from 646444444645 its reverse (546444444646), we obtain a palindrome (99999999999).

The spelling of 646444444645 in words is "six hundred forty-six billion, four hundred forty-four million, four hundred forty-four thousand, six hundred forty-five".