161605523 has 2 divisors, whose sum is σ = 161605524. Its totient is φ = 161605522.

The previous prime is 161605517. The next prime is 161605571. The reversal of 161605523 is 325506161.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 161605523 - 2⁶ = 161605459 is a prime.

It is a super-2 number, since 2×161605523² = 52232690128207058, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (161605513) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80802761 + 80802762.

It is an arithmetic number, because the mean of its divisors is an integer number (80802762).

Almost surely, 2^161605523 is an apocalyptic number.

161605523 is a deficient number, since it is larger than the sum of its proper divisors (1).

161605523 is an equidigital number, since it uses as much as digits as its factorization.

161605523 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5400, while the sum is 29.

The square root of 161605523 is about 12712.4160960850. The cubic root of 161605523 is about 544.6933414969.

The spelling of 161605523 in words is "one hundred sixty-one million, six hundred five thousand, five hundred twenty-three".