640066613 has 2 divisors, whose sum is σ = 640066614. Its totient is φ = 640066612.

The previous prime is 640066573. The next prime is 640066619. The reversal of 640066613 is 316660046.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 337897924 + 302168689 = 18382^2 + 17383^2 .

It is a cyclic number.

It is not a de Polignac number, because 640066613 - 2²² = 635872309 is a prime.

It is a super-3 number, since 3×640066613³ (a number of 27 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 640066613.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (640066619) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320033306 + 320033307.

It is an arithmetic number, because the mean of its divisors is an integer number (320033307).

Almost surely, 2^640066613 is an apocalyptic number.

It is an amenable number.

640066613 is a deficient number, since it is larger than the sum of its proper divisors (1).

640066613 is an equidigital number, since it uses as much as digits as its factorization.

640066613 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15552, while the sum is 32.

The square root of 640066613 is about 25299.5378021022. The cubic root of 640066613 is about 861.8037735918.

The spelling of 640066613 in words is "six hundred forty million, sixty-six thousand, six hundred thirteen".