12121621 has 8 divisors (see below), whose sum is σ = 12683520. Its totient is φ = 11562672.

The previous prime is 12121619. The next prime is 12121631. The reversal of 12121621 is 12612121.

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

It is a cyclic number.

It is not a de Polignac number, because 12121621 - 2¹ = 12121619 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12121595 and 12121604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12121631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16171 + ... + 16903.

It is an arithmetic number, because the mean of its divisors is an integer number (1585440).

Almost surely, 2^12121621 is an apocalyptic number.

It is an amenable number.

12121621 is a deficient number, since it is larger than the sum of its proper divisors (561899).

12121621 is an equidigital number, since it uses as much as digits as its factorization.

12121621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1475.

The product of its digits is 48, while the sum is 16.

The square root of 12121621 is about 3481.6118393641. The cubic root of 12121621 is about 229.7137017420.

Adding to 12121621 its reverse (12612121), we get a palindrome (24733742).

The spelling of 12121621 in words is "twelve million, one hundred twenty-one thousand, six hundred twenty-one".