642709605757 has 2 divisors, whose sum is σ = 642709605758. Its totient is φ = 642709605756.

The previous prime is 642709605751. The next prime is 642709605787. The reversal of 642709605757 is 757506907246.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 616875151396 + 25834454361 = 785414^2 + 160731^2 .

It is a cyclic number.

It is not a de Polignac number, because 642709605757 - 2³⁹ = 92953791869 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (642709605751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321354802878 + 321354802879.

It is an arithmetic number, because the mean of its divisors is an integer number (321354802879).

Almost surely, 2^642709605757 is an apocalyptic number.

It is an amenable number.

642709605757 is a deficient number, since it is larger than the sum of its proper divisors (1).

642709605757 is an equidigital number, since it uses as much as digits as its factorization.

642709605757 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 22226400, while the sum is 58.

The spelling of 642709605757 in words is "six hundred forty-two billion, seven hundred nine million, six hundred five thousand, seven hundred fifty-seven".