121005 has 12 divisors (see below), whose sum is σ = 209820. Its totient is φ = 64512.

The previous prime is 121001. The next prime is 121007. The reversal of 121005 is 500121.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 19881 + 101124 = 141^2 + 318^2 .

It is not a de Polignac number, because 121005 - 2² = 121001 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121001) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1300 + ... + 1389.

It is an arithmetic number, because the mean of its divisors is an integer number (17485).

2¹²¹⁰⁰⁵ is an apocalyptic number.

121005 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

121005 is a deficient number, since it is larger than the sum of its proper divisors (88815).

121005 is a wasteful number, since it uses less digits than its factorization.

121005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2700 (or 2697 counting only the distinct ones).

The product of its (nonzero) digits is 10, while the sum is 9.

The square root of 121005 is about 347.8577295390. The cubic root of 121005 is about 49.4615557024.

Adding to 121005 its reverse (500121), we get a palindrome (621126).

The spelling of 121005 in words is "one hundred twenty-one thousand, five".