121381 has 4 divisors (see below), whose sum is σ = 130732. Its totient is φ = 112032.

The previous prime is 121379. The next prime is 121403. The reversal of 121381 is 183121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 183121 = 149 ⋅1229.

It can be written as a sum of positive squares in 2 ways, for example, as 70756 + 50625 = 266^2 + 225^2 .

It is a cyclic number.

It is not a de Polignac number, because 121381 - 2¹ = 121379 is a prime.

It is a super-2 number, since 2×121381² = 29466694322, which contains 22 as substring.

It is a Duffinian number.

It is a nialpdrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121321) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4656 + ... + 4681.

It is an arithmetic number, because the mean of its divisors is an integer number (32683).

2¹²¹³⁸¹ is an apocalyptic number.

It is an amenable number.

121381 is a deficient number, since it is larger than the sum of its proper divisors (9351).

121381 is an equidigital number, since it uses as much as digits as its factorization.

121381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9350.

The product of its digits is 48, while the sum is 16.

The square root of 121381 is about 348.3977611868. The cubic root of 121381 is about 49.5127335197.

The spelling of 121381 in words is "one hundred twenty-one thousand, three hundred eighty-one".