646875141578645 has 24 divisors (see below), whose sum is σ = 904014521104824. Its totient is φ = 443065742695296.

The previous prime is 646875141578587. The next prime is 646875141578693. The reversal of 646875141578645 is 546875141578646.

It can be written as a sum of positive squares in 4 ways, for example, as 107630623732324 + 539244517846321 = 10374518^2 + 23221639^2 .

It is not a de Polignac number, because 646875141578645 - 2¹⁴ = 646875141562261 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1505091122 + ... + 1505520851.

It is an arithmetic number, because the mean of its divisors is an integer number (37667271712701).

Almost surely, 2^{646875141578645} is an apocalyptic number.

It is an amenable number.

646875141578645 is a deficient number, since it is larger than the sum of its proper divisors (257139379526179).

646875141578645 is a wasteful number, since it uses less digits than its factorization.

646875141578645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3010612869 (or 3010612862 counting only the distinct ones).

The product of its digits is 5419008000, while the sum is 77.

Subtracting from 646875141578645 its reverse (546875141578646), we obtain a palindrome (99999999999999).

The spelling of 646875141578645 in words is "six hundred forty-six trillion, eight hundred seventy-five billion, one hundred forty-one million, five hundred seventy-eight thousand, six hundred forty-five".