12129621 has 8 divisors (see below), whose sum is σ = 18483264. Its totient is φ = 6931200.

The previous prime is 12129617. The next prime is 12129659. The reversal of 12129621 is 12692121.

12129621 is digitally balanced in base 2 and base 3, 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 12129621 - 2² = 12129617 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 12129591 and 12129600.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12129661) 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, 288780 + ... + 288821.

It is an arithmetic number, because the mean of its divisors is an integer number (2310408).

Almost surely, 2^12129621 is an apocalyptic number.

It is an amenable number.

12129621 is a deficient number, since it is larger than the sum of its proper divisors (6353643).

12129621 is an equidigital number, since it uses as much as digits as its factorization.

12129621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 577611.

The product of its digits is 432, while the sum is 24.

The square root of 12129621 is about 3482.7605430176. The cubic root of 12129621 is about 229.7642259383.

Subtracting 12129621 from its reverse (12692121), we obtain a square (562500 = 750²).

It can be divided in two parts, 121296 and 21, that multiplied together give a square (2547216 = 1596²).

The spelling of 12129621 in words is "twelve million, one hundred twenty-nine thousand, six hundred twenty-one".