642856997933 has 2 divisors, whose sum is σ = 642856997934. Its totient is φ = 642856997932.

The previous prime is 642856997921. The next prime is 642856997953. The reversal of 642856997933 is 339799658246.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 617288348329 + 25568649604 = 785677^2 + 159902^2 .

It is a cyclic number.

It is not a de Polignac number, because 642856997933 - 2¹⁶ = 642856932397 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (642856997953) 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, 321428498966 + 321428498967.

It is an arithmetic number, because the mean of its divisors is an integer number (321428498967).

Almost surely, 2^642856997933 is an apocalyptic number.

It is an amenable number.

642856997933 is a deficient number, since it is larger than the sum of its proper divisors (1).

642856997933 is an equidigital number, since it uses as much as digits as its factorization.

642856997933 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 529079040, while the sum is 71.

The spelling of 642856997933 in words is "six hundred forty-two billion, eight hundred fifty-six million, nine hundred ninety-seven thousand, nine hundred thirty-three".