646897667388 has 144 divisors (see below), whose sum is σ = 1957001921280. Its totient is φ = 164800065024.

The previous prime is 646897667387. The next prime is 646897667399. The reversal of 646897667388 is 883766798646.

646897667388 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646897667387) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1513120 + ... + 1892967.

It is an arithmetic number, because the mean of its divisors is an integer number (13590291120).

Almost surely, 2^646897667388 is an apocalyptic number.

646897667388 is a gapful number since it is divisible by the number (68) formed by its first and last digit.

It is an amenable number.

646897667388 is an abundant number, since it is smaller than the sum of its proper divisors (1310104253892).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

646897667388 is a wasteful number, since it uses less digits than its factorization.

646897667388 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3406144 (or 3406135 counting only the distinct ones).

The product of its digits is 3511517184, while the sum is 78.

The spelling of 646897667388 in words is "six hundred forty-six billion, eight hundred ninety-seven million, six hundred sixty-seven thousand, three hundred eighty-eight".