642123 has 6 divisors (see below), whose sum is σ = 927524. Its totient is φ = 428076.

The previous prime is 642121. The next prime is 642133. The reversal of 642123 is 321246.

It is a happy number.

642123 is a `hidden beast` number, since 642 + 1 + 23 = 666.

642123 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 642123 - 2¹ = 642121 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 642096 and 642105.

It is not an unprimeable number, because it can be changed into a prime (642121) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 35665 + ... + 35682.

2⁶⁴²¹²³ is an apocalyptic number.

642123 is a deficient number, since it is larger than the sum of its proper divisors (285401).

642123 is a wasteful number, since it uses less digits than its factorization.

642123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71353 (or 71350 counting only the distinct ones).

The product of its digits is 288, while the sum is 18.

The square root of 642123 is about 801.3257764480. The cubic root of 642123 is about 86.2725712823.

Adding to 642123 its product of digits (288), we get a triangular number (642411 = T₁₁₃₃).

Adding to 642123 its reverse (321246), we get a palindrome (963369).

It can be divided in two parts, 64 and 2123, that added together give a 7-th power (2187 = 3⁷).

The spelling of 642123 in words is "six hundred forty-two thousand, one hundred twenty-three".