121728899 has 2 divisors, whose sum is σ = 121728900. Its totient is φ = 121728898.

The previous prime is 121728881. The next prime is 121728907. The reversal of 121728899 is 998827121.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 121728899 - 2²⁴ = 104951683 is a prime.

It is not a weakly prime, because it can be changed into another prime (121724899) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60864449 + 60864450.

It is an arithmetic number, because the mean of its divisors is an integer number (60864450).

Almost surely, 2^121728899 is an apocalyptic number.

121728899 is a deficient number, since it is larger than the sum of its proper divisors (1).

121728899 is an equidigital number, since it uses as much as digits as its factorization.

121728899 is an evil number, because the sum of its binary digits is even.

The product of its digits is 145152, while the sum is 47.

The square root of 121728899 is about 11033.0820263424. The cubic root of 121728899 is about 495.5999242513.

The spelling of 121728899 in words is "one hundred twenty-one million, seven hundred twenty-eight thousand, eight hundred ninety-nine".