121728881 has 2 divisors, whose sum is σ = 121728882. Its totient is φ = 121728880.

The previous prime is 121728797. The next prime is 121728899. The reversal of 121728881 is 188827121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 87984400 + 33744481 = 9380^2 + 5809^2 .

It is a cyclic number.

It is not a de Polignac number, because 121728881 - 2¹⁰ = 121727857 is a prime.

It is a super-2 number, since 2×121728881² = 29635840939024322, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (121728281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60864440 + 60864441.

It is an arithmetic number, because the mean of its divisors is an integer number (60864441).

Almost surely, 2^121728881 is an apocalyptic number.

It is an amenable number.

121728881 is a deficient number, since it is larger than the sum of its proper divisors (1).

121728881 is an equidigital number, since it uses as much as digits as its factorization.

121728881 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 14336, while the sum is 38.

The square root of 121728881 is about 11033.0812106138. The cubic root of 121728881 is about 495.5998998233.

The spelling of 121728881 in words is "one hundred twenty-one million, seven hundred twenty-eight thousand, eight hundred eighty-one".