861004644761 has 2 divisors, whose sum is σ = 861004644762. Its totient is φ = 861004644760.

The previous prime is 861004644751. The next prime is 861004644959. The reversal of 861004644761 is 167446400168.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 781491360400 + 79513284361 = 884020^2 + 281981^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-861004644761 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (861004644751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 430502322380 + 430502322381.

It is an arithmetic number, because the mean of its divisors is an integer number (430502322381).

Almost surely, 2^861004644761 is an apocalyptic number.

It is an amenable number.

861004644761 is a deficient number, since it is larger than the sum of its proper divisors (1).

861004644761 is an equidigital number, since it uses as much as digits as its factorization.

861004644761 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 774144, while the sum is 47.

The spelling of 861004644761 in words is "eight hundred sixty-one billion, four million, six hundred forty-four thousand, seven hundred sixty-one".