161315533 has 4 divisors (see below), whose sum is σ = 170804700. Its totient is φ = 151826368.

The previous prime is 161315513. The next prime is 161315543. The reversal of 161315533 is 335513161.

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 67864644 + 93450889 = 8238^2 + 9667^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161315533 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161315503) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4744558 + ... + 4744591.

It is an arithmetic number, because the mean of its divisors is an integer number (42701175).

Almost surely, 2^161315533 is an apocalyptic number.

It is an amenable number.

161315533 is a deficient number, since it is larger than the sum of its proper divisors (9489167).

161315533 is an equidigital number, since it uses as much as digits as its factorization.

161315533 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9489166.

The product of its digits is 4050, while the sum is 28.

The square root of 161315533 is about 12701.0051964402. The cubic root of 161315533 is about 544.3673415071.

Adding to 161315533 its reverse (335513161), we get a palindrome (496828694).

The spelling of 161315533 in words is "one hundred sixty-one million, three hundred fifteen thousand, five hundred thirty-three".