645879031813 has 16 divisors (see below), whose sum is σ = 671988960000. Its totient is φ = 620230658112.

The previous prime is 645879031801. The next prime is 645879031841. The reversal of 645879031813 is 318130978546.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-645879031813 is a prime.

It is a super-3 number, since 3×645879031813³ (a number of 36 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645879031013) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7848243 + ... + 7930111.

It is an arithmetic number, because the mean of its divisors is an integer number (41999310000).

Almost surely, 2^645879031813 is an apocalyptic number.

It is an amenable number.

645879031813 is a deficient number, since it is larger than the sum of its proper divisors (26109928187).

645879031813 is a wasteful number, since it uses less digits than its factorization.

645879031813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84684.

The product of its (nonzero) digits is 4354560, while the sum is 55.

The spelling of 645879031813 in words is "six hundred forty-five billion, eight hundred seventy-nine million, thirty-one thousand, eight hundred thirteen".