121556055 has 16 divisors (see below), whose sum is σ = 199013760. Its totient is φ = 63321888.

The previous prime is 121556051. The next prime is 121556089. The reversal of 121556055 is 550655121.

It is not a de Polignac number, because 121556055 - 2² = 121556051 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121556051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 93585 + ... + 94874.

It is an arithmetic number, because the mean of its divisors is an integer number (12438360).

Almost surely, 2^121556055 is an apocalyptic number.

121556055 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

121556055 is a deficient number, since it is larger than the sum of its proper divisors (77457705).

121556055 is a wasteful number, since it uses less digits than its factorization.

121556055 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 188510.

The product of its (nonzero) digits is 7500, while the sum is 30.

The square root of 121556055 is about 11025.2462557532. The cubic root of 121556055 is about 495.3652441552.

The spelling of 121556055 in words is "one hundred twenty-one million, five hundred fifty-six thousand, fifty-five".