161520523 has 2 divisors, whose sum is σ = 161520524. Its totient is φ = 161520522.

The previous prime is 161520481. The next prime is 161520533. The reversal of 161520523 is 325025161.

It is a strong prime.

It is an emirp because it is prime and its reverse (325025161) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161520523 is a prime.

It is not a weakly prime, because it can be changed into another prime (161520533) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80760261 + 80760262.

It is an arithmetic number, because the mean of its divisors is an integer number (80760262).

Almost surely, 2^161520523 is an apocalyptic number.

161520523 is a deficient number, since it is larger than the sum of its proper divisors (1).

161520523 is an equidigital number, since it uses as much as digits as its factorization.

161520523 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1800, while the sum is 25.

The square root of 161520523 is about 12709.0724681229. The cubic root of 161520523 is about 544.5978269112.

Adding to 161520523 its reverse (325025161), we get a palindrome (486545684).

The spelling of 161520523 in words is "one hundred sixty-one million, five hundred twenty thousand, five hundred twenty-three".