642735017 has 2 divisors, whose sum is σ = 642735018. Its totient is φ = 642735016.

The previous prime is 642734971. The next prime is 642735019. The reversal of 642735017 is 710537246.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 642571801 + 163216 = 25349^2 + 404^2 .

It is a cyclic number.

It is not a de Polignac number, because 642735017 - 2¹⁴ = 642718633 is a prime.

Together with 642735019, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (642735019) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321367508 + 321367509.

It is an arithmetic number, because the mean of its divisors is an integer number (321367509).

Almost surely, 2^642735017 is an apocalyptic number.

It is an amenable number.

642735017 is a deficient number, since it is larger than the sum of its proper divisors (1).

642735017 is an equidigital number, since it uses as much as digits as its factorization.

642735017 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 35280, while the sum is 35.

The square root of 642735017 is about 25352.2191730823. The cubic root of 642735017 is about 862.9997180333. Note that the first 3 decimals are identical.

The spelling of 642735017 in words is "six hundred forty-two million, seven hundred thirty-five thousand, seventeen".