8159181973 has 2 divisors, whose sum is σ = 8159181974. Its totient is φ = 8159181972.

The previous prime is 8159181949. The next prime is 8159181983. The reversal of 8159181973 is 3791819518.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6486208369 + 1672973604 = 80537^2 + 40902^2 .

It is a cyclic number.

It is not a de Polignac number, because 8159181973 - 2⁹ = 8159181461 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 8159181973.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8159181983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4079590986 + 4079590987.

It is an arithmetic number, because the mean of its divisors is an integer number (4079590987).

Almost surely, 2^8159181973 is an apocalyptic number.

It is an amenable number.

8159181973 is a deficient number, since it is larger than the sum of its proper divisors (1).

8159181973 is an equidigital number, since it uses as much as digits as its factorization.

8159181973 is an evil number, because the sum of its binary digits is even.

The product of its digits is 544320, while the sum is 52.

The square root of 8159181973 is about 90328.1903560566. The cubic root of 8159181973 is about 2013.1781419901.

The spelling of 8159181973 in words is "eight billion, one hundred fifty-nine million, one hundred eighty-one thousand, nine hundred seventy-three".