642224123 has 4 divisors (see below), whose sum is σ = 657888168. Its totient is φ = 626560080.

The previous prime is 642224081. The next prime is 642224131. The reversal of 642224123 is 321422246.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-642224123 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 642224092 and 642224101.

It is not an unprimeable number, because it can be changed into a prime (642224173) 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 in 3 ways as a sum of consecutive naturals, for example, 7831961 + ... + 7832042.

It is an arithmetic number, because the mean of its divisors is an integer number (164472042).

Almost surely, 2^642224123 is an apocalyptic number.

642224123 is a deficient number, since it is larger than the sum of its proper divisors (15664045).

642224123 is a wasteful number, since it uses less digits than its factorization.

642224123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15664044.

The product of its digits is 4608, while the sum is 26.

The square root of 642224123 is about 25342.1412473374. The cubic root of 642224123 is about 862.7709984530.

Adding to 642224123 its reverse (321422246), we get a palindrome (963646369).

The spelling of 642224123 in words is "six hundred forty-two million, two hundred twenty-four thousand, one hundred twenty-three".