8161473772009 has 2 divisors, whose sum is σ = 8161473772010. Its totient is φ = 8161473772008.

The previous prime is 8161473771967. The next prime is 8161473772031. The reversal of 8161473772009 is 9002773741618.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 4233038779225 + 3928434992784 = 2057435^2 + 1982028^2 .

It is a cyclic number.

It is not a de Polignac number, because 8161473772009 - 2¹⁵ = 8161473739241 is a prime.

It is not a weakly prime, because it can be changed into another prime (8161473772069) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4080736886004 + 4080736886005.

It is an arithmetic number, because the mean of its divisors is an integer number (4080736886005).

Almost surely, 2^{8161473772009} is an apocalyptic number.

It is an amenable number.

8161473772009 is a deficient number, since it is larger than the sum of its proper divisors (1).

8161473772009 is an equidigital number, since it uses as much as digits as its factorization.

8161473772009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3556224, while the sum is 55.

The spelling of 8161473772009 in words is "eight trillion, one hundred sixty-one billion, four hundred seventy-three million, seven hundred seventy-two thousand, nine".