128121161 has 16 divisors (see below), whose sum is σ = 154492800. Its totient is φ = 103794048.

The previous prime is 128121151. The next prime is 128121211. The reversal of 128121161 is 161121821.

It is a cyclic number.

It is not a de Polignac number, because 128121161 - 2¹⁰ = 128120137 is a prime.

It is not an unprimeable number, because it can be changed into a prime (128121151) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 74831 + ... + 76523.

It is an arithmetic number, because the mean of its divisors is an integer number (9655800).

Almost surely, 2^128121161 is an apocalyptic number.

It is an amenable number.

128121161 is a deficient number, since it is larger than the sum of its proper divisors (26371639).

128121161 is a wasteful number, since it uses less digits than its factorization.

128121161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2288.

The product of its digits is 192, while the sum is 23.

The square root of 128121161 is about 11319.0618427500. The cubic root of 128121161 is about 504.1273836600.

Adding to 128121161 its reverse (161121821), we get a palindrome (289242982).

The spelling of 128121161 in words is "one hundred twenty-eight million, one hundred twenty-one thousand, one hundred sixty-one".