121512505 has 16 divisors (see below), whose sum is σ = 154486080.
Its totient is φ = 91495872.
The previous prime is 121512497. The next prime is 121512509. The reversal of 121512505 is 505215121.
It is a happy number.
It is a cyclic number.
It is not a de Polignac number, because 121512505 - 23 = 121512497 is a prime.
It is not an unprimeable number, because it can be changed into a prime (121512509) by changing a digit.
It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10842 + ... + 18988.
It is an arithmetic number, because the mean of its divisors is an integer number (9655380).
Almost surely, 2121512505 is an apocalyptic number.
It is an amenable number.
121512505 is a deficient number, since it is larger than the sum of its proper divisors (32973575).
121512505 is a wasteful number, since it uses less digits than its factorization.
121512505 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 8328.
The product of its (nonzero) digits is 500, while the sum is 22.
The square root of 121512505 is about 11023.2710662489.
The cubic root of 121512505 is about 495.3060787678.
Adding to 121512505 its reverse (505215121), we get a palindrome (626727626).
The spelling of 121512505 in words is "one hundred twenty-one million, five hundred twelve thousand, five hundred five".