121391441 has 4 divisors (see below), whose sum is σ = 128532132. Its totient is φ = 114250752.

The previous prime is 121391429. The next prime is 121391449. The reversal of 121391441 is 144193121.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 144193121 = 31 ⋅4651391.

It can be written as a sum of positive squares in 2 ways, for example, as 113529025 + 7862416 = 10655^2 + 2804^2 .

It is a cyclic number.

It is not a de Polignac number, because 121391441 - 2¹⁴ = 121375057 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 121391441.

It is not an unprimeable number, because it can be changed into a prime (121391449) 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 3 ways as a sum of consecutive naturals, for example, 3570320 + ... + 3570353.

It is an arithmetic number, because the mean of its divisors is an integer number (32133033).

Almost surely, 2^121391441 is an apocalyptic number.

It is an amenable number.

121391441 is a deficient number, since it is larger than the sum of its proper divisors (7140691).

121391441 is an equidigital number, since it uses as much as digits as its factorization.

121391441 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7140690.

The product of its digits is 864, while the sum is 26.

The square root of 121391441 is about 11017.7784058312. The cubic root of 121391441 is about 495.1415314776.

The spelling of 121391441 in words is "one hundred twenty-one million, three hundred ninety-one thousand, four hundred forty-one".