121155555 has 8 divisors (see below), whose sum is σ = 193848912. Its totient is φ = 64616288.

The previous prime is 121155511. The next prime is 121155581. The reversal of 121155555 is 555551121.

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 121155555 - 2⁸ = 121155299 is a prime.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 4038504 + ... + 4038533.

It is an arithmetic number, because the mean of its divisors is an integer number (24231114).

Almost surely, 2^121155555 is an apocalyptic number.

121155555 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

121155555 is a deficient number, since it is larger than the sum of its proper divisors (72693357).

121155555 is an equidigital number, since it uses as much as digits as its factorization.

121155555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8077045.

The product of its digits is 6250, while the sum is 30.

The square root of 121155555 is about 11007.0684107986. The cubic root of 121155555 is about 494.8206063536.

The spelling of 121155555 in words is "one hundred twenty-one million, one hundred fifty-five thousand, five hundred fifty-five".