121555331 has 4 divisors (see below), whose sum is σ = 127953000. Its totient is φ = 115157664.

The previous prime is 121555319. The next prime is 121555333. The reversal of 121555331 is 133555121.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 121555331 - 2⁶ = 121555267 is a prime.

It is a super-2 number, since 2×121555331² = 29551396989039122, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 121555331.

It is not an unprimeable number, because it can be changed into a prime (121555333) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3198806 + ... + 3198843.

It is an arithmetic number, because the mean of its divisors is an integer number (31988250).

Almost surely, 2^121555331 is an apocalyptic number.

121555331 is a deficient number, since it is larger than the sum of its proper divisors (6397669).

121555331 is an equidigital number, since it uses as much as digits as its factorization.

121555331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6397668.

The product of its digits is 2250, while the sum is 26.

The square root of 121555331 is about 11025.2134219706. The cubic root of 121555331 is about 495.3642606716.

The spelling of 121555331 in words is "one hundred twenty-one million, five hundred fifty-five thousand, three hundred thirty-one".