161321123203 has 2 divisors, whose sum is σ = 161321123204. Its totient is φ = 161321123202.

The previous prime is 161321123153. The next prime is 161321123213. The reversal of 161321123203 is 302321123161.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161321123203 is a prime.

It is not a weakly prime, because it can be changed into another prime (161321123213) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80660561601 + 80660561602.

It is an arithmetic number, because the mean of its divisors is an integer number (80660561602).

Almost surely, 2^161321123203 is an apocalyptic number.

161321123203 is a deficient number, since it is larger than the sum of its proper divisors (1).

161321123203 is an equidigital number, since it uses as much as digits as its factorization.

161321123203 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1296, while the sum is 25.

Adding to 161321123203 its reverse (302321123161), we get a palindrome (463642246364).

The spelling of 161321123203 in words is "one hundred sixty-one billion, three hundred twenty-one million, one hundred twenty-three thousand, two hundred three".