645441646020 has 24 divisors (see below), whose sum is σ = 1807236609024. Its totient is φ = 172117772256.

The previous prime is 645441645997. The next prime is 645441646021. The reversal of 645441646020 is 20646144546.

645441646020 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (645441646021) 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, 5378680324 + ... + 5378680443.

It is an arithmetic number, because the mean of its divisors is an integer number (75301525376).

Almost surely, 2^645441646020 is an apocalyptic number.

645441646020 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

645441646020 is an abundant number, since it is smaller than the sum of its proper divisors (1161794963004).

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

645441646020 is a wasteful number, since it uses less digits than its factorization.

645441646020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10757360779 (or 10757360777 counting only the distinct ones).

The product of its (nonzero) digits is 552960, while the sum is 42.

The spelling of 645441646020 in words is "six hundred forty-five billion, four hundred forty-one million, six hundred forty-six thousand, twenty".