646854875644 has 48 divisors (see below), whose sum is σ = 1185287040000. Its totient is φ = 308300262336.

The previous prime is 646854875633. The next prime is 646854875647. The reversal of 646854875644 is 446578458646.

It is a super-3 number, since 3×646854875644³ (a number of 36 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 646854875644.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646854875647) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32998054 + ... + 33017650.

It is an arithmetic number, because the mean of its divisors is an integer number (24693480000).

Almost surely, 2^646854875644 is an apocalyptic number.

It is an amenable number.

646854875644 is a deficient number, since it is larger than the sum of its proper divisors (538432164356).

646854875644 is a wasteful number, since it uses less digits than its factorization.

646854875644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20842 (or 20840 counting only the distinct ones).

The product of its digits is 619315200, while the sum is 67.

The spelling of 646854875644 in words is "six hundred forty-six billion, eight hundred fifty-four million, eight hundred seventy-five thousand, six hundred forty-four".