121355405 has 4 divisors (see below), whose sum is σ = 145626492. Its totient is φ = 97084320.

The previous prime is 121355371. The next prime is 121355411. The reversal of 121355405 is 504553121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 504553121 = 9397 ⋅53693.

It can be written as a sum of positive squares in 2 ways, for example, as 54213769 + 67141636 = 7363^2 + 8194^2 .

It is not a de Polignac number, because 121355405 - 2²⁰ = 120306829 is a prime.

It is a Duffinian number.

It is a congruent number.

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 3 ways as a sum of consecutive naturals, for example, 12135536 + ... + 12135545.

It is an arithmetic number, because the mean of its divisors is an integer number (36406623).

Almost surely, 2^121355405 is an apocalyptic number.

It is an amenable number.

121355405 is a deficient number, since it is larger than the sum of its proper divisors (24271087).

121355405 is an equidigital number, since it uses as much as digits as its factorization.

121355405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24271086.

The product of its (nonzero) digits is 3000, while the sum is 26.

The square root of 121355405 is about 11016.1429275405. The cubic root of 121355405 is about 495.0925310814.

The spelling of 121355405 in words is "one hundred twenty-one million, three hundred fifty-five thousand, four hundred five".