642605317 has 2 divisors, whose sum is σ = 642605318. Its totient is φ = 642605316.

The previous prime is 642605297. The next prime is 642605323. The reversal of 642605317 is 713506246.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 567106596 + 75498721 = 23814^2 + 8689^2 .

It is a cyclic number.

It is not a de Polignac number, because 642605317 - 2⁷ = 642605189 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (642605357) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321302658 + 321302659.

It is an arithmetic number, because the mean of its divisors is an integer number (321302659).

Almost surely, 2^642605317 is an apocalyptic number.

It is an amenable number.

642605317 is a deficient number, since it is larger than the sum of its proper divisors (1).

642605317 is an equidigital number, since it uses as much as digits as its factorization.

642605317 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 30240, while the sum is 34.

The square root of 642605317 is about 25349.6610825470. The cubic root of 642605317 is about 862.9416647712.

It can be divided in two parts, 6426053 and 17, that multiplied together give a palindrome (109242901).

The spelling of 642605317 in words is "six hundred forty-two million, six hundred five thousand, three hundred seventeen".