642954239 has 2 divisors, whose sum is σ = 642954240. Its totient is φ = 642954238.

The previous prime is 642954223. The next prime is 642954283. The reversal of 642954239 is 932459246.

It is an a-pointer prime, because the next prime (642954283) can be obtained adding 642954239 to its sum of digits (44).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 642954239 - 2⁴ = 642954223 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 642954239.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (642950239) 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, 321477119 + 321477120.

It is an arithmetic number, because the mean of its divisors is an integer number (321477120).

Almost surely, 2^642954239 is an apocalyptic number.

642954239 is a deficient number, since it is larger than the sum of its proper divisors (1).

642954239 is an equidigital number, since it uses as much as digits as its factorization.

642954239 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 466560, while the sum is 44.

The square root of 642954239 is about 25356.5423313195. The cubic root of 642954239 is about 863.0978232731.

The spelling of 642954239 in words is "six hundred forty-two million, nine hundred fifty-four thousand, two hundred thirty-nine".