642215266657 has 2 divisors, whose sum is σ = 642215266658. Its totient is φ = 642215266656.

The previous prime is 642215266597. The next prime is 642215266703. The reversal of 642215266657 is 756662512246.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 612469020816 + 29746245841 = 782604^2 + 172471^2 .

It is a cyclic number.

It is not a de Polignac number, because 642215266657 - 2³⁵ = 607855528289 is a prime.

It is not a weakly prime, because it can be changed into another prime (642215261657) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321107633328 + 321107633329.

It is an arithmetic number, because the mean of its divisors is an integer number (321107633329).

Almost surely, 2^642215266657 is an apocalyptic number.

It is an amenable number.

642215266657 is a deficient number, since it is larger than the sum of its proper divisors (1).

642215266657 is an equidigital number, since it uses as much as digits as its factorization.

642215266657 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7257600, while the sum is 52.

The spelling of 642215266657 in words is "six hundred forty-two billion, two hundred fifteen million, two hundred sixty-six thousand, six hundred fifty-seven".