645413281868 has 6 divisors (see below), whose sum is σ = 1129473243276. Its totient is φ = 322706640932.

The previous prime is 645413281829. The next prime is 645413281879. The reversal of 645413281868 is 868182314546.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80676660230 + ... + 80676660237.

It is an arithmetic number, because the mean of its divisors is an integer number (188245540546).

Almost surely, 2^645413281868 is an apocalyptic number.

It is an amenable number.

645413281868 is a deficient number, since it is larger than the sum of its proper divisors (484059961408).

645413281868 is a wasteful number, since it uses less digits than its factorization.

645413281868 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 161353320471 (or 161353320469 counting only the distinct ones).

The product of its digits is 8847360, while the sum is 56.

The spelling of 645413281868 in words is "six hundred forty-five billion, four hundred thirteen million, two hundred eighty-one thousand, eight hundred sixty-eight".