16161121 has 2 divisors, whose sum is σ = 16161122. Its totient is φ = 16161120.

The previous prime is 16161107. The next prime is 16161127. The reversal of 16161121 is 12116161.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10962721 + 5198400 = 3311^2 + 2280^2 .

It is a cyclic number.

It is not a de Polignac number, because 16161121 - 2⁹ = 16160609 is a prime.

It is a super-2 number, since 2×16161121² = 522363663953282, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (16161127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8080560 + 8080561.

It is an arithmetic number, because the mean of its divisors is an integer number (8080561).

Almost surely, 2^16161121 is an apocalyptic number.

It is an amenable number.

16161121 is a deficient number, since it is larger than the sum of its proper divisors (1).

16161121 is an equidigital number, since it uses as much as digits as its factorization.

16161121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 72, while the sum is 19.

The square root of 16161121 is about 4020.0896756167. The cubic root of 16161121 is about 252.8272188102.

Adding to 16161121 its reverse (12116161), we get a palindrome (28277282).

The spelling of 16161121 in words is "sixteen million, one hundred sixty-one thousand, one hundred twenty-one".