861727831 has 2 divisors, whose sum is σ = 861727832. Its totient is φ = 861727830.

The previous prime is 861727793. The next prime is 861727861. The reversal of 861727831 is 138727168.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 861727831 - 2¹¹ = 861725783 is a prime.

It is a super-2 number, since 2×861727831² = 1485149709439929122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (861727861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 430863915 + 430863916.

It is an arithmetic number, because the mean of its divisors is an integer number (430863916).

Almost surely, 2^861727831 is an apocalyptic number.

861727831 is a deficient number, since it is larger than the sum of its proper divisors (1).

861727831 is an equidigital number, since it uses as much as digits as its factorization.

861727831 is an evil number, because the sum of its binary digits is even.

The product of its digits is 112896, while the sum is 43.

The square root of 861727831 is about 29355.2010894151. The cubic root of 861727831 is about 951.6049807463.

The spelling of 861727831 in words is "eight hundred sixty-one million, seven hundred twenty-seven thousand, eight hundred thirty-one".