645835689818 has 32 divisors (see below), whose sum is σ = 1072698951168. Its totient is φ = 289152270000.

The previous prime is 645835689773. The next prime is 645835689827. The reversal of 645835689818 is 818986538546.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 26889971 + ... + 26913977.

It is an arithmetic number, because the mean of its divisors is an integer number (33521842224).

Almost surely, 2^645835689818 is an apocalyptic number.

645835689818 is a deficient number, since it is larger than the sum of its proper divisors (426863261350).

645835689818 is a wasteful number, since it uses less digits than its factorization.

645835689818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42338.

The product of its digits is 398131200, while the sum is 71.

The spelling of 645835689818 in words is "six hundred forty-five billion, eight hundred thirty-five million, six hundred eighty-nine thousand, eight hundred eighteen".