12121615 has 16 divisors (see below), whose sum is σ = 16132896. Its totient is φ = 8668800.

The previous prime is 12121583. The next prime is 12121619. The reversal of 12121615 is 51612121.

It is not a de Polignac number, because 12121615 - 2⁵ = 12121583 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12121592 and 12121601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12121619) 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, 1549 + ... + 5161.

It is an arithmetic number, because the mean of its divisors is an integer number (1008306).

Almost surely, 2^12121615 is an apocalyptic number.

12121615 is a deficient number, since it is larger than the sum of its proper divisors (4011281).

12121615 is a wasteful number, since it uses less digits than its factorization.

12121615 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3690.

The product of its digits is 120, while the sum is 19.

The square root of 12121615 is about 3481.6109776941. The cubic root of 12121615 is about 229.7136638405.

Adding to 12121615 its reverse (51612121), we get a palindrome (63733736).

It can be divided in two parts, 121 and 21615, that added together give a triangular number (21736 = T₂₀₈).

The spelling of 12121615 in words is "twelve million, one hundred twenty-one thousand, six hundred fifteen".