640068017 has 2 divisors, whose sum is σ = 640068018. Its totient is φ = 640068016.

The previous prime is 640067957. The next prime is 640068073. The reversal of 640068017 is 710860046.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 391406656 + 248661361 = 19784^2 + 15769^2 .

It is a cyclic number.

It is not a de Polignac number, because 640068017 - 2¹⁶ = 640002481 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (640058017) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320034008 + 320034009.

It is an arithmetic number, because the mean of its divisors is an integer number (320034009).

Almost surely, 2^640068017 is an apocalyptic number.

It is an amenable number.

640068017 is a deficient number, since it is larger than the sum of its proper divisors (1).

640068017 is an equidigital number, since it uses as much as digits as its factorization.

640068017 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8064, while the sum is 32.

The square root of 640068017 is about 25299.5655496295. The cubic root of 640068017 is about 861.8044037197.

The spelling of 640068017 in words is "six hundred forty million, sixty-eight thousand, seventeen".