121518 has 24 divisors (see below), whose sum is σ = 271128. Its totient is φ = 39312.

The previous prime is 121507. The next prime is 121523. The reversal of 121518 is 815121.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a nialpdrome in base 11.

It is a self number, because there is not a number n which added to its sum of digits gives 121518.

It is a congruent number.

It is an unprimeable number.

121518 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 696 + ... + 852.

It is an arithmetic number, because the mean of its divisors is an integer number (11297).

2¹²¹⁵¹⁸ is an apocalyptic number.

121518 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

121518 is an abundant number, since it is smaller than the sum of its proper divisors (149610).

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

121518 is a wasteful number, since it uses less digits than its factorization.

121518 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 208 (or 205 counting only the distinct ones).

The product of its digits is 80, while the sum is 18.

The square root of 121518 is about 348.5943200914. The cubic root of 121518 is about 49.5313544847.

Adding to 121518 its reverse (815121), we get a palindrome (936639).

The spelling of 121518 in words is "one hundred twenty-one thousand, five hundred eighteen".