641964959 has 2 divisors, whose sum is σ = 641964960. Its totient is φ = 641964958.

The previous prime is 641964949. The next prime is 641964979. The reversal of 641964959 is 959469146.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 641964959 - 2⁸ = 641964703 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 641964959.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (641964949) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320982479 + 320982480.

It is an arithmetic number, because the mean of its divisors is an integer number (320982480).

Almost surely, 2^641964959 is an apocalyptic number.

641964959 is a deficient number, since it is larger than the sum of its proper divisors (1).

641964959 is an equidigital number, since it uses as much as digits as its factorization.

641964959 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2099520, while the sum is 53.

The square root of 641964959 is about 25337.0274302255. The cubic root of 641964959 is about 862.6549282427.

The spelling of 641964959 in words is "six hundred forty-one million, nine hundred sixty-four thousand, nine hundred fifty-nine".