640343101 has 2 divisors, whose sum is σ = 640343102. Its totient is φ = 640343100.

The previous prime is 640343071. The next prime is 640343129. The reversal of 640343101 is 101343046.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 640140601 + 202500 = 25301^2 + 450^2 .

It is a cyclic number.

It is not a de Polignac number, because 640343101 - 2¹⁷ = 640212029 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (640343141) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320171550 + 320171551.

It is an arithmetic number, because the mean of its divisors is an integer number (320171551).

Almost surely, 2^640343101 is an apocalyptic number.

It is an amenable number.

640343101 is a deficient number, since it is larger than the sum of its proper divisors (1).

640343101 is an equidigital number, since it uses as much as digits as its factorization.

640343101 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 864, while the sum is 22.

The square root of 640343101 is about 25305.0015016795. The cubic root of 640343101 is about 861.9278461469.

Adding to 640343101 its reverse (101343046), we get a palindrome (741686147).

The spelling of 640343101 in words is "six hundred forty million, three hundred forty-three thousand, one hundred one".