642423242 has 4 divisors (see below), whose sum is σ = 963634866. Its totient is φ = 321211620.

The previous prime is 642423239. The next prime is 642423289. The reversal of 642423242 is 242324246.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 242324246 = 2 ⋅121162123.

It can be written as a sum of positive squares in only one way, i.e., 620059801 + 22363441 = 24901^2 + 4729^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160605809 + ... + 160605812.

Almost surely, 2^642423242 is an apocalyptic number.

642423242 is a deficient number, since it is larger than the sum of its proper divisors (321211624).

642423242 is a wasteful number, since it uses less digits than its factorization.

642423242 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 321211623.

The product of its digits is 18432, while the sum is 29.

The square root of 642423242 is about 25346.0695572312. The cubic root of 642423242 is about 862.8601554625.

Adding to 642423242 its reverse (242324246), we get a palindrome (884747488).

The spelling of 642423242 in words is "six hundred forty-two million, four hundred twenty-three thousand, two hundred forty-two".