1919966161 has 2 divisors, whose sum is σ = 1919966162. Its totient is φ = 1919966160.

The previous prime is 1919966143. The next prime is 1919966177. The reversal of 1919966161 is 1616699191.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1161514561 + 758451600 = 34081^2 + 27540^2 .

It is an emirp because it is prime and its reverse (1616699191) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1919966161 - 2¹⁹ = 1919441873 is a prime.

1919966161 is a strobogrammatic number because it is the same when read upside-down.

It is not a weakly prime, because it can be changed into another prime (1919966861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 959983080 + 959983081.

It is an arithmetic number, because the mean of its divisors is an integer number (959983081).

Almost surely, 2^1919966161 is an apocalyptic number.

It is an amenable number.

1919966161 is a deficient number, since it is larger than the sum of its proper divisors (1).

1919966161 is an equidigital number, since it uses as much as digits as its factorization.

1919966161 is an evil number, because the sum of its binary digits is even.

The product of its digits is 157464, while the sum is 49.

The square root of 1919966161 is about 43817.4184657198. The cubic root of 1919966161 is about 1242.8857005580.

The spelling of 1919966161 in words is "one billion, nine hundred nineteen million, nine hundred sixty-six thousand, one hundred sixty-one".