161301521 has 2 divisors, whose sum is σ = 161301522. Its totient is φ = 161301520.

The previous prime is 161301499. The next prime is 161301523. The reversal of 161301521 is 125103161.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 131446225 + 29855296 = 11465^2 + 5464^2 .

It is a cyclic number.

It is not a de Polignac number, because 161301521 - 2¹⁸ = 161039377 is a prime.

Together with 161301523, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 161301493 and 161301502.

It is not a weakly prime, because it can be changed into another prime (161301523) 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, 80650760 + 80650761.

It is an arithmetic number, because the mean of its divisors is an integer number (80650761).

Almost surely, 2^161301521 is an apocalyptic number.

It is an amenable number.

161301521 is a deficient number, since it is larger than the sum of its proper divisors (1).

161301521 is an equidigital number, since it uses as much as digits as its factorization.

161301521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 180, while the sum is 20.

The square root of 161301521 is about 12700.4535745776. The cubic root of 161301521 is about 544.3515796522.

Adding to 161301521 its reverse (125103161), we get a palindrome (286404682).

The spelling of 161301521 in words is "one hundred sixty-one million, three hundred one thousand, five hundred twenty-one".