646887788647 has 8 divisors (see below), whose sum is σ = 648251768736. Its totient is φ = 645523955712.

The previous prime is 646887788609. The next prime is 646887788669. The reversal of 646887788647 is 746887788646.

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 646887788647 - 2³⁵ = 612528050279 is a prime.

It is a super-2 number, since 2×646887788647² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646887788347) 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, 16468743 + ... + 16507975.

It is an arithmetic number, because the mean of its divisors is an integer number (81031471092).

Almost surely, 2^646887788647 is an apocalyptic number.

646887788647 is a deficient number, since it is larger than the sum of its proper divisors (1363980089).

646887788647 is a wasteful number, since it uses less digits than its factorization.

646887788647 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73577.

The product of its digits is 4855431168, while the sum is 79.

Subtracting 646887788647 from its reverse (746887788646), we obtain a palindrome (99999999999).

The spelling of 646887788647 in words is "six hundred forty-six billion, eight hundred eighty-seven million, seven hundred eighty-eight thousand, six hundred forty-seven".