121540 has 24 divisors (see below), whose sum is σ = 262080. Its totient is φ = 47328.

The previous prime is 121531. The next prime is 121547. The reversal of 121540 is 45121.

It is a self number, because there is not a number n which added to its sum of digits gives 121540.

It is not an unprimeable number, because it can be changed into a prime (121547) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1129 + ... + 1231.

It is an arithmetic number, because the mean of its divisors is an integer number (10920).

2¹²¹⁵⁴⁰ is an apocalyptic number.

121540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

121540 is an abundant number, since it is smaller than the sum of its proper divisors (140540).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

121540 is a wasteful number, since it uses less digits than its factorization.

With its predecessor (121539) it forms an eRAP, since the sums of their prime factors are consecutive (170 and 171).

121540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 171 (or 169 counting only the distinct ones).

The product of its (nonzero) digits is 40, while the sum is 13.

The square root of 121540 is about 348.6258739681. The cubic root of 121540 is about 49.5343434083.

Adding to 121540 its reverse (45121), we get a palindrome (166661).

The spelling of 121540 in words is "one hundred twenty-one thousand, five hundred forty".