1971590161 has 2 divisors, whose sum is σ = 1971590162. Its totient is φ = 1971590160.

The previous prime is 1971590141. The next prime is 1971590167. The reversal of 1971590161 is 1610951791.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1580539536 + 391050625 = 39756^2 + 19775^2 .

It is an emirp because it is prime and its reverse (1610951791) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1971590161 - 2⁵ = 1971590129 is a prime.

It is not a weakly prime, because it can be changed into another prime (1971590167) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 985795080 + 985795081.

It is an arithmetic number, because the mean of its divisors is an integer number (985795081).

Almost surely, 2^1971590161 is an apocalyptic number.

It is an amenable number.

1971590161 is a deficient number, since it is larger than the sum of its proper divisors (1).

1971590161 is an equidigital number, since it uses as much as digits as its factorization.

1971590161 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 17010, while the sum is 40.

The square root of 1971590161 is about 44402.5918275048. The cubic root of 1971590161 is about 1253.9268850872.

The spelling of 1971590161 in words is "one billion, nine hundred seventy-one million, five hundred ninety thousand, one hundred sixty-one".