121515515 has 16 divisors (see below), whose sum is σ = 161775360. Its totient is φ = 86874720.

The previous prime is 121515497. The next prime is 121515517. The reversal of 121515515 is 515515121.

It is not a de Polignac number, because 121515515 - 2⁸ = 121515259 is a prime.

It is not an unprimeable number, because it can be changed into a prime (121515517) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15479 + ... + 21968.

It is an arithmetic number, because the mean of its divisors is an integer number (10110960).

Almost surely, 2^121515515 is an apocalyptic number.

121515515 is a deficient number, since it is larger than the sum of its proper divisors (40259845).

121515515 is a wasteful number, since it uses less digits than its factorization.

121515515 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37522.

The product of its digits is 1250, while the sum is 26.

The square root of 121515515 is about 11023.4075947504. The cubic root of 121515515 is about 495.3101684950.

The spelling of 121515515 in words is "one hundred twenty-one million, five hundred fifteen thousand, five hundred fifteen".