640081073 has 2 divisors, whose sum is σ = 640081074. Its totient is φ = 640081072.

The previous prime is 640081033. The next prime is 640081097. The reversal of 640081073 is 370180046.

640081073 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 618616384 + 21464689 = 24872^2 + 4633^2 .

It is a cyclic number.

It is not a de Polignac number, because 640081073 - 2¹² = 640076977 is a prime.

It is not a weakly prime, because it can be changed into another prime (640081003) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320040536 + 320040537.

It is an arithmetic number, because the mean of its divisors is an integer number (320040537).

Almost surely, 2^640081073 is an apocalyptic number.

It is an amenable number.

640081073 is a deficient number, since it is larger than the sum of its proper divisors (1).

640081073 is an equidigital number, since it uses as much as digits as its factorization.

640081073 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4032, while the sum is 29.

The square root of 640081073 is about 25299.8235764600. The cubic root of 640081073 is about 861.8102633271.

The spelling of 640081073 in words is "six hundred forty million, eighty-one thousand, seventy-three".