121321381 has 4 divisors (see below), whose sum is σ = 121343500. Its totient is φ = 121299264.

The previous prime is 121321379. The next prime is 121321391. The reversal of 121321381 is 183123121.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 183123121 = 19 ⋅9638059.

It can be written as a sum of positive squares in 2 ways, for example, as 56776225 + 64545156 = 7535^2 + 8034^2 .

It is a cyclic number.

It is not a de Polignac number, because 121321381 - 2¹ = 121321379 is a prime.

It is a super-2 number, since 2×121321381² = 29437754975494322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121321351) 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, 4045 + ... + 16093.

It is an arithmetic number, because the mean of its divisors is an integer number (30335875).

Almost surely, 2^121321381 is an apocalyptic number.

It is an amenable number.

121321381 is a deficient number, since it is larger than the sum of its proper divisors (22119).

121321381 is a wasteful number, since it uses less digits than its factorization.

121321381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22118.

The product of its digits is 288, while the sum is 22.

The square root of 121321381 is about 11014.5985401194. The cubic root of 121321381 is about 495.0462576232.

The spelling of 121321381 in words is "one hundred twenty-one million, three hundred twenty-one thousand, three hundred eighty-one".