161644313 has 4 divisors (see below), whose sum is σ = 171152820. Its totient is φ = 152135808.

The previous prime is 161644297. The next prime is 161644321. The reversal of 161644313 is 313446161.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 150601984 + 11042329 = 12272^2 + 3323^2 .

It is a cyclic number.

It is not a de Polignac number, because 161644313 - 2⁴ = 161644297 is a prime.

It is a super-2 number, since 2×161644313² = 52257767850483938, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161644333) 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, 4754228 + ... + 4754261.

It is an arithmetic number, because the mean of its divisors is an integer number (42788205).

Almost surely, 2^161644313 is an apocalyptic number.

It is an amenable number.

161644313 is a deficient number, since it is larger than the sum of its proper divisors (9508507).

161644313 is an equidigital number, since it uses as much as digits as its factorization.

161644313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9508506.

The product of its digits is 5184, while the sum is 29.

The square root of 161644313 is about 12713.9416783309. The cubic root of 161644313 is about 544.7369187296.

The spelling of 161644313 in words is "one hundred sixty-one million, six hundred forty-four thousand, three hundred thirteen".