161873893 has 2 divisors, whose sum is σ = 161873894. Its totient is φ = 161873892.

The previous prime is 161873879. The next prime is 161873903. The reversal of 161873893 is 398378161.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 148791204 + 13082689 = 12198^2 + 3617^2 .

It is an emirp because it is prime and its reverse (398378161) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 161873893 - 2⁹ = 161873381 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161873843) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80936946 + 80936947.

It is an arithmetic number, because the mean of its divisors is an integer number (80936947).

Almost surely, 2^161873893 is an apocalyptic number.

It is an amenable number.

161873893 is a deficient number, since it is larger than the sum of its proper divisors (1).

161873893 is an equidigital number, since it uses as much as digits as its factorization.

161873893 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 217728, while the sum is 46.

The square root of 161873893 is about 12722.9671460709. The cubic root of 161873893 is about 544.9946895086.

The spelling of 161873893 in words is "one hundred sixty-one million, eight hundred seventy-three thousand, eight hundred ninety-three".