645113129 has 4 divisors (see below), whose sum is σ = 645966084. Its totient is φ = 644260176.

The previous prime is 645113123. The next prime is 645113197. The reversal of 645113129 is 921311546.

645113129 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 921311546 = 2 ⋅460655773.

It can be written as a sum of positive squares in 2 ways, for example, as 137827600 + 507285529 = 11740^2 + 22523^2 .

It is a cyclic number.

It is not a de Polignac number, because 645113129 - 2⁴ = 645113113 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 645113095 and 645113104.

It is not an unprimeable number, because it can be changed into a prime (645113123) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 425342 + ... + 426855.

It is an arithmetic number, because the mean of its divisors is an integer number (161491521).

Almost surely, 2^645113129 is an apocalyptic number.

It is an amenable number.

645113129 is a deficient number, since it is larger than the sum of its proper divisors (852955).

645113129 is an equidigital number, since it uses as much as digits as its factorization.

645113129 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 852954.

The product of its digits is 6480, while the sum is 32.

The square root of 645113129 is about 25399.0773257613. The cubic root of 645113129 is about 864.0627709489.

The spelling of 645113129 in words is "six hundred forty-five million, one hundred thirteen thousand, one hundred twenty-nine".