646027720647 has 8 divisors (see below), whose sum is σ = 861997663344. Its totient is φ = 430371462528.

The previous prime is 646027720627. The next prime is 646027720649. The reversal of 646027720647 is 746027720646.

646027720647 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 not a de Polignac number, because 646027720647 - 2¹¹ = 646027718599 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 646027720647.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646027720649) 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, 78416338 + ... + 78424575.

It is an arithmetic number, because the mean of its divisors is an integer number (107749707918).

Almost surely, 2^646027720647 is an apocalyptic number.

646027720647 is a deficient number, since it is larger than the sum of its proper divisors (215969942697).

646027720647 is a wasteful number, since it uses less digits than its factorization.

646027720647 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 156842289.

The product of its (nonzero) digits is 4741632, while the sum is 51.

Subtracting 646027720647 from its reverse (746027720646), we obtain a palindrome (99999999999).

The spelling of 646027720647 in words is "six hundred forty-six billion, twenty-seven million, seven hundred twenty thousand, six hundred forty-seven".