8312819861 has 2 divisors, whose sum is σ = 8312819862. Its totient is φ = 8312819860.

The previous prime is 8312819857. The next prime is 8312819863. The reversal of 8312819861 is 1689182138.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6572344900 + 1740474961 = 81070^2 + 41719^2 .

It is a cyclic number.

It is not a de Polignac number, because 8312819861 - 2² = 8312819857 is a prime.

Together with 8312819863, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8312819863) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4156409930 + 4156409931.

It is an arithmetic number, because the mean of its divisors is an integer number (4156409931).

Almost surely, 2^8312819861 is an apocalyptic number.

It is an amenable number.

8312819861 is a deficient number, since it is larger than the sum of its proper divisors (1).

8312819861 is an equidigital number, since it uses as much as digits as its factorization.

8312819861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 165888, while the sum is 47.

The square root of 8312819861 is about 91174.6667720809. Note that the first 3 decimals coincide. The cubic root of 8312819861 is about 2025.7357372066.

The spelling of 8312819861 in words is "eight billion, three hundred twelve million, eight hundred nineteen thousand, eight hundred sixty-one".