121728655 has 4 divisors (see below), whose sum is σ = 146074392. Its totient is φ = 97382920.

The previous prime is 121728647. The next prime is 121728671. The reversal of 121728655 is 556827121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 556827121 = 283 ⋅1967587.

It is not a de Polignac number, because 121728655 - 2³ = 121728647 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12172861 + ... + 12172870.

It is an arithmetic number, because the mean of its divisors is an integer number (36518598).

Almost surely, 2^121728655 is an apocalyptic number.

121728655 is a deficient number, since it is larger than the sum of its proper divisors (24345737).

121728655 is an equidigital number, since it uses as much as digits as its factorization.

121728655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24345736.

The product of its digits is 33600, while the sum is 37.

The square root of 121728655 is about 11033.0709686832. The cubic root of 121728655 is about 495.5995931153.

The spelling of 121728655 in words is "one hundred twenty-one million, seven hundred twenty-eight thousand, six hundred fifty-five".