861449934881 has 2 divisors, whose sum is σ = 861449934882. Its totient is φ = 861449934880.

The previous prime is 861449934869. The next prime is 861449934899. The reversal of 861449934881 is 188439944168.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 601375434256 + 260074500625 = 775484^2 + 509975^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-861449934881 is a prime.

It is a super-2 number, since 2×861449934881² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (861449934841) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 430724967440 + 430724967441.

It is an arithmetic number, because the mean of its divisors is an integer number (430724967441).

Almost surely, 2^861449934881 is an apocalyptic number.

It is an amenable number.

861449934881 is a deficient number, since it is larger than the sum of its proper divisors (1).

861449934881 is an equidigital number, since it uses as much as digits as its factorization.

861449934881 is an evil number, because the sum of its binary digits is even.

The product of its digits is 47775744, while the sum is 65.

The spelling of 861449934881 in words is "eight hundred sixty-one billion, four hundred forty-nine million, nine hundred thirty-four thousand, eight hundred eighty-one".