642043123 has 2 divisors, whose sum is σ = 642043124. Its totient is φ = 642043122.

The previous prime is 642043109. The next prime is 642043141. The reversal of 642043123 is 321340246.

642043123 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 642043123 - 2²⁵ = 608488691 is a prime.

It is not a weakly prime, because it can be changed into another prime (642043153) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321021561 + 321021562.

It is an arithmetic number, because the mean of its divisors is an integer number (321021562).

Almost surely, 2^642043123 is an apocalyptic number.

642043123 is a deficient number, since it is larger than the sum of its proper divisors (1).

642043123 is an equidigital number, since it uses as much as digits as its factorization.

642043123 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3456, while the sum is 25.

The square root of 642043123 is about 25338.5698688778. The cubic root of 642043123 is about 862.6899383692.

Adding to 642043123 its reverse (321340246), we get a palindrome (963383369).

The spelling of 642043123 in words is "six hundred forty-two million, forty-three thousand, one hundred twenty-three".