121421155 has 4 divisors (see below), whose sum is σ = 145705392. Its totient is φ = 97136920.

The previous prime is 121421137. The next prime is 121421159. The reversal of 121421155 is 551124121.

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

It is not a de Polignac number, because 121421155 - 2¹¹ = 121419107 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121421159) 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 3 ways as a sum of consecutive naturals, for example, 12142111 + ... + 12142120.

It is an arithmetic number, because the mean of its divisors is an integer number (36426348).

Almost surely, 2^121421155 is an apocalyptic number.

121421155 is a deficient number, since it is larger than the sum of its proper divisors (24284237).

121421155 is an equidigital number, since it uses as much as digits as its factorization.

121421155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24284236.

The product of its digits is 400, while the sum is 22.

The square root of 121421155 is about 11019.1267802853. The cubic root of 121421155 is about 495.1819281620.

Adding to 121421155 its reverse (551124121), we get a palindrome (672545276).

The spelling of 121421155 in words is "one hundred twenty-one million, four hundred twenty-one thousand, one hundred fifty-five".