121855521 has 8 divisors (see below), whose sum is σ = 162671040. Its totient is φ = 81138512.

The previous prime is 121855519. The next prime is 121855523. The reversal of 121855521 is 125558121.

It is an interprime number because it is at equal distance from previous prime (121855519) and next prime (121855523).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 121855521 - 2¹ = 121855519 is a prime.

It is not an unprimeable number, because it can be changed into a prime (121855523) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21690 + ... + 26723.

It is an arithmetic number, because the mean of its divisors is an integer number (20333880).

Almost surely, 2^121855521 is an apocalyptic number.

It is an amenable number.

121855521 is a deficient number, since it is larger than the sum of its proper divisors (40815519).

121855521 is an equidigital number, since it uses as much as digits as its factorization.

121855521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49255.

The product of its digits is 4000, while the sum is 30.

The square root of 121855521 is about 11038.8188226821. The cubic root of 121855521 is about 495.7717051730.

Adding to 121855521 its product of digits (4000), we get a square (121859521 = 11039²).

The spelling of 121855521 in words is "one hundred twenty-one million, eight hundred fifty-five thousand, five hundred twenty-one".