642538454309 has 2 divisors, whose sum is σ = 642538454310. Its totient is φ = 642538454308.

The previous prime is 642538454219. The next prime is 642538454317. The reversal of 642538454309 is 903454835246.

It is a happy number.

642538454309 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 542712156100 + 99826298209 = 736690^2 + 315953^2 .

It is a cyclic number.

It is not a de Polignac number, because 642538454309 - 2³⁶ = 573818977573 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (642538454359) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321269227154 + 321269227155.

It is an arithmetic number, because the mean of its divisors is an integer number (321269227155).

Almost surely, 2^642538454309 is an apocalyptic number.

It is an amenable number.

642538454309 is a deficient number, since it is larger than the sum of its proper divisors (1).

642538454309 is an equidigital number, since it uses as much as digits as its factorization.

642538454309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12441600, while the sum is 53.

The spelling of 642538454309 in words is "six hundred forty-two billion, five hundred thirty-eight million, four hundred fifty-four thousand, three hundred nine".