640371161 has 2 divisors, whose sum is σ = 640371162. Its totient is φ = 640371160.

The previous prime is 640371143. The next prime is 640371227. The reversal of 640371161 is 161173046.

640371161 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 397603600 + 242767561 = 19940^2 + 15581^2 .

It is a cyclic number.

It is not a de Polignac number, because 640371161 - 2⁶ = 640371097 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (640371101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320185580 + 320185581.

It is an arithmetic number, because the mean of its divisors is an integer number (320185581).

Almost surely, 2^640371161 is an apocalyptic number.

It is an amenable number.

640371161 is a deficient number, since it is larger than the sum of its proper divisors (1).

640371161 is an equidigital number, since it uses as much as digits as its factorization.

640371161 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3024, while the sum is 29.

The square root of 640371161 is about 25305.5559314551. Note that the first 3 decimals coincide. The cubic root of 640371161 is about 861.9404359299.

The spelling of 640371161 in words is "six hundred forty million, three hundred seventy-one thousand, one hundred sixty-one".