642218444513 has 2 divisors, whose sum is σ = 642218444514. Its totient is φ = 642218444512.

The previous prime is 642218444477. The next prime is 642218444519. The reversal of 642218444513 is 315444812246.

It is a happy number.

642218444513 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., 606261562384 + 35956882129 = 778628^2 + 189623^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-642218444513 is a prime.

It is not a weakly prime, because it can be changed into another prime (642218444519) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321109222256 + 321109222257.

It is an arithmetic number, because the mean of its divisors is an integer number (321109222257).

Almost surely, 2^642218444513 is an apocalyptic number.

It is an amenable number.

642218444513 is a deficient number, since it is larger than the sum of its proper divisors (1).

642218444513 is an equidigital number, since it uses as much as digits as its factorization.

642218444513 is an evil number, because the sum of its binary digits is even.

The product of its digits is 737280, while the sum is 44.

The spelling of 642218444513 in words is "six hundred forty-two billion, two hundred eighteen million, four hundred forty-four thousand, five hundred thirteen".