861131611 has 2 divisors, whose sum is σ = 861131612. Its totient is φ = 861131610.

The previous prime is 861131581. The next prime is 861131627. The reversal of 861131611 is 116131168.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 861131611 - 2⁷ = 861131483 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 861131611.

It is not a weakly prime, because it can be changed into another prime (861131911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 430565805 + 430565806.

It is an arithmetic number, because the mean of its divisors is an integer number (430565806).

Almost surely, 2^861131611 is an apocalyptic number.

861131611 is a deficient number, since it is larger than the sum of its proper divisors (1).

861131611 is an equidigital number, since it uses as much as digits as its factorization.

861131611 is an evil number, because the sum of its binary digits is even.

The product of its digits is 864, while the sum is 28.

The square root of 861131611 is about 29345.0440619877. The cubic root of 861131611 is about 951.3854617741.

Adding to 861131611 its reverse (116131168), we get a palindrome (977262779).

The spelling of 861131611 in words is "eight hundred sixty-one million, one hundred thirty-one thousand, six hundred eleven".