642215417 has 2 divisors, whose sum is σ = 642215418. Its totient is φ = 642215416.

The previous prime is 642215351. The next prime is 642215419. The reversal of 642215417 is 714512246.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 349839616 + 292375801 = 18704^2 + 17099^2 .

It is a cyclic number.

It is not a de Polignac number, because 642215417 - 2¹⁰ = 642214393 is a prime.

Together with 642215419, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (642215419) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321107708 + 321107709.

It is an arithmetic number, because the mean of its divisors is an integer number (321107709).

Almost surely, 2^642215417 is an apocalyptic number.

It is an amenable number.

642215417 is a deficient number, since it is larger than the sum of its proper divisors (1).

642215417 is an equidigital number, since it uses as much as digits as its factorization.

642215417 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13440, while the sum is 32.

The square root of 642215417 is about 25341.9694775288. The cubic root of 642215417 is about 862.7670998564.

The spelling of 642215417 in words is "six hundred forty-two million, two hundred fifteen thousand, four hundred seventeen".