646115511645 has 64 divisors (see below), whose sum is σ = 1155592381440. Its totient is φ = 342515257344.

The previous prime is 646115511637. The next prime is 646115511721. The reversal of 646115511645 is 546115511646.

It is a happy number.

646115511645 is a `hidden beast` number, since 6 + 4 + 61 + 15 + 511 + 64 + 5 = 666.

It is not a de Polignac number, because 646115511645 - 2³ = 646115511637 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 646115511645.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 32220012 + ... + 32240058.

It is an arithmetic number, because the mean of its divisors is an integer number (18056130960).

Almost surely, 2^646115511645 is an apocalyptic number.

It is an amenable number.

646115511645 is a deficient number, since it is larger than the sum of its proper divisors (509476869795).

646115511645 is a wasteful number, since it uses less digits than its factorization.

646115511645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21491 (or 21485 counting only the distinct ones).

The product of its digits is 432000, while the sum is 45.

Subtracting from 646115511645 its reverse (546115511646), we obtain a palindrome (99999999999).

The spelling of 646115511645 in words is "six hundred forty-six billion, one hundred fifteen million, five hundred eleven thousand, six hundred forty-five".