645115217810 has 24 divisors (see below), whose sum is σ = 1350792273420. Its totient is φ = 221182360224.

The previous prime is 645115217797. The next prime is 645115217863. The reversal of 645115217810 is 18712511546.

645115217810 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 617590085161 + 27525132649 = 785869^2 + 165907^2 .

It is a super-2 number, since 2×645115217810² (a number of 24 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 658280345 + ... + 658281324.

Almost surely, 2^645115217810 is an apocalyptic number.

645115217810 is an abundant number, since it is smaller than the sum of its proper divisors (705677055610).

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

645115217810 is a wasteful number, since it uses less digits than its factorization.

645115217810 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1316561690 (or 1316561683 counting only the distinct ones).

The product of its (nonzero) digits is 67200, while the sum is 41.

The spelling of 645115217810 in words is "six hundred forty-five billion, one hundred fifteen million, two hundred seventeen thousand, eight hundred ten".