820767641 has 2 divisors, whose sum is σ = 820767642. Its totient is φ = 820767640.

The previous prime is 820767631. The next prime is 820767653. The reversal of 820767641 is 146767028.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 718454416 + 102313225 = 26804^2 + 10115^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-820767641 is a prime.

It is not a weakly prime, because it can be changed into another prime (820767631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410383820 + 410383821.

It is an arithmetic number, because the mean of its divisors is an integer number (410383821).

Almost surely, 2^820767641 is an apocalyptic number.

It is an amenable number.

820767641 is a deficient number, since it is larger than the sum of its proper divisors (1).

820767641 is an equidigital number, since it uses as much as digits as its factorization.

820767641 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 112896, while the sum is 41.

The square root of 820767641 is about 28649.0425843518. The cubic root of 820767641 is about 936.2821461889.

The spelling of 820767641 in words is "eight hundred twenty million, seven hundred sixty-seven thousand, six hundred forty-one".