645311311533 has 24 divisors (see below), whose sum is σ = 1065883685568. Its totient is φ = 368538904512.

The previous prime is 645311311531. The next prime is 645311311549. The reversal of 645311311533 is 335113113546.

645311311533 is a `hidden beast` number, since 6 + 4 + 5 + 3 + 113 + 1 + 1 + 533 = 666.

It is not a de Polignac number, because 645311311533 - 2¹ = 645311311531 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645311311531) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 2811135 + ... + 3032012.

It is an arithmetic number, because the mean of its divisors is an integer number (44411820232).

Almost surely, 2^645311311533 is an apocalyptic number.

645311311533 is a gapful number since it is divisible by the number (63) formed by its first and last digit.

It is an amenable number.

645311311533 is a deficient number, since it is larger than the sum of its proper divisors (420572374035).

645311311533 is a wasteful number, since it uses less digits than its factorization.

645311311533 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5844913 (or 5844910 counting only the distinct ones).

The product of its digits is 48600, while the sum is 36.

It can be divided in two parts, 6453113 and 11533, that added together give a palindrome (6464646).

The spelling of 645311311533 in words is "six hundred forty-five billion, three hundred eleven million, three hundred eleven thousand, five hundred thirty-three".