161656249 has 4 divisors (see below), whose sum is σ = 161720820. Its totient is φ = 161591680.

The previous prime is 161656207. The next prime is 161656267. The reversal of 161656249 is 942656161.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 942656161 = 139 ⋅6781699.

It can be written as a sum of positive squares in 2 ways, for example, as 113103225 + 48553024 = 10635^2 + 6968^2 .

It is a cyclic number.

It is not a de Polignac number, because 161656249 - 2¹³ = 161648057 is a prime.

It is a super-2 number, since 2×161656249² = 52265485681500002, which contains 22 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161656549) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28372 + ... + 33589.

It is an arithmetic number, because the mean of its divisors is an integer number (40430205).

Almost surely, 2^161656249 is an apocalyptic number.

It is an amenable number.

161656249 is a deficient number, since it is larger than the sum of its proper divisors (64571).

161656249 is an equidigital number, since it uses as much as digits as its factorization.

161656249 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64570.

The product of its digits is 77760, while the sum is 40.

The square root of 161656249 is about 12714.4110756260. The cubic root of 161656249 is about 544.7503263976.

The spelling of 161656249 in words is "one hundred sixty-one million, six hundred fifty-six thousand, two hundred forty-nine".