642754009 has 2 divisors, whose sum is σ = 642754010. Its totient is φ = 642754008.

The previous prime is 642753971. The next prime is 642754051. The reversal of 642754009 is 900457246.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 389944009 + 252810000 = 19747^2 + 15900^2 .

It is a cyclic number.

It is not a de Polignac number, because 642754009 - 2²⁹ = 105883097 is a prime.

It is not a weakly prime, because it can be changed into another prime (642754069) 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, 321377004 + 321377005.

It is an arithmetic number, because the mean of its divisors is an integer number (321377005).

Almost surely, 2^642754009 is an apocalyptic number.

It is an amenable number.

642754009 is a deficient number, since it is larger than the sum of its proper divisors (1).

642754009 is an equidigital number, since it uses as much as digits as its factorization.

642754009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 60480, while the sum is 37.

The square root of 642754009 is about 25352.5937331864. The cubic root of 642754009 is about 863.0082181299.

The spelling of 642754009 in words is "six hundred forty-two million, seven hundred fifty-four thousand, nine".