641676961 has 2 divisors, whose sum is σ = 641676962. Its totient is φ = 641676960.

The previous prime is 641676923. The next prime is 641677013. The reversal of 641676961 is 169676146.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 540795025 + 100881936 = 23255^2 + 10044^2 .

It is a cyclic number.

It is not a de Polignac number, because 641676961 - 2²³ = 633288353 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (641676461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320838480 + 320838481.

It is an arithmetic number, because the mean of its divisors is an integer number (320838481).

Almost surely, 2^641676961 is an apocalyptic number.

It is an amenable number.

641676961 is a deficient number, since it is larger than the sum of its proper divisors (1).

641676961 is an equidigital number, since it uses as much as digits as its factorization.

641676961 is an evil number, because the sum of its binary digits is even.

The product of its digits is 326592, while the sum is 46.

The square root of 641676961 is about 25331.3434503581. The cubic root of 641676961 is about 862.5259076724.

It can be divided in two parts, 64 and 1676961, that added together give a square (1677025 = 1295²).

The spelling of 641676961 in words is "six hundred forty-one million, six hundred seventy-six thousand, nine hundred sixty-one".