121515 has 8 divisors (see below), whose sum is σ = 194448. Its totient is φ = 64800.

The previous prime is 121507. The next prime is 121523. The reversal of 121515 is 515121.

It is an interprime number because it is at equal distance from previous prime (121507) and next prime (121523).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 121515 - 2³ = 121507 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (15), and also a Moran number because the ratio is a prime number: 8101 = 121515 / (1 + 2 + 1 + 5 + 1 + 5).

It is a junction number, because it is equal to n+sod(n) for n = 121494 and 121503.

It is an unprimeable 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 7 ways as a sum of consecutive naturals, for example, 4036 + ... + 4065.

It is an arithmetic number, because the mean of its divisors is an integer number (24306).

2¹²¹⁵¹⁵ is an apocalyptic number.

121515 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

121515 is a deficient number, since it is larger than the sum of its proper divisors (72933).

121515 is an equidigital number, since it uses as much as digits as its factorization.

121515 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8109.

The product of its digits is 50, while the sum is 15.

The square root of 121515 is about 348.5900170688. The cubic root of 121515 is about 49.5309468762.

Adding to 121515 its reverse (515121), we get a palindrome (636636).

It can be divided in two parts, 1215 and 15, that multiplied together give a square (18225 = 135²).

The spelling of 121515 in words is "one hundred twenty-one thousand, five hundred fifteen".