645122323123 has 2 divisors, whose sum is σ = 645122323124. Its totient is φ = 645122323122.

The previous prime is 645122323073. The next prime is 645122323159. The reversal of 645122323123 is 321323221546.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-645122323123 is a prime.

It is a super-4 number, since 4×645122323123⁴ (a number of 48 digits) contains 4444 as substring.

It is not a weakly prime, because it can be changed into another prime (645122323423) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322561161561 + 322561161562.

It is an arithmetic number, because the mean of its divisors is an integer number (322561161562).

Almost surely, 2^645122323123 is an apocalyptic number.

645122323123 is a deficient number, since it is larger than the sum of its proper divisors (1).

645122323123 is an equidigital number, since it uses as much as digits as its factorization.

645122323123 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 51840, while the sum is 34.

Adding to 645122323123 its reverse (321323221546), we get a palindrome (966445544669).

The spelling of 645122323123 in words is "six hundred forty-five billion, one hundred twenty-two million, three hundred twenty-three thousand, one hundred twenty-three".