12121665 has 8 divisors (see below), whose sum is σ = 19394688. Its totient is φ = 6464880.

The previous prime is 12121661. The next prime is 12121673. The reversal of 12121665 is 56612121.

12121665 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 12121665 - 2² = 12121661 is a prime.

It is not an unprimeable number, because it can be changed into a prime (12121661) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 404041 + ... + 404070.

It is an arithmetic number, because the mean of its divisors is an integer number (2424336).

Almost surely, 2^12121665 is an apocalyptic number.

12121665 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

12121665 is a deficient number, since it is larger than the sum of its proper divisors (7273023).

12121665 is an equidigital number, since it uses as much as digits as its factorization.

12121665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 808119.

The product of its digits is 720, while the sum is 24.

The square root of 12121665 is about 3481.6181582707. The cubic root of 12121665 is about 229.7139796858.

Adding to 12121665 its reverse (56612121), we get a palindrome (68733786).

The spelling of 12121665 in words is "twelve million, one hundred twenty-one thousand, six hundred sixty-five".