161565793 has 2 divisors, whose sum is σ = 161565794. Its totient is φ = 161565792.

The previous prime is 161565787. The next prime is 161565821. The reversal of 161565793 is 397565161.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 99361024 + 62204769 = 9968^2 + 7887^2 .

It is a cyclic number.

It is not a de Polignac number, because 161565793 - 2⁹ = 161565281 is a prime.

It is a super-2 number, since 2×161565793² = 52207010935437698, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (161568793) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80782896 + 80782897.

It is an arithmetic number, because the mean of its divisors is an integer number (80782897).

Almost surely, 2^161565793 is an apocalyptic number.

It is an amenable number.

161565793 is a deficient number, since it is larger than the sum of its proper divisors (1).

161565793 is an equidigital number, since it uses as much as digits as its factorization.

161565793 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 170100, while the sum is 43.

The square root of 161565793 is about 12710.8533545156. The cubic root of 161565793 is about 544.6487010256.

The spelling of 161565793 in words is "one hundred sixty-one million, five hundred sixty-five thousand, seven hundred ninety-three".