12151621 has 12 divisors (see below), whose sum is σ = 13153644. Its totient is φ = 11217600.

The previous prime is 12151603. The next prime is 12151637. The reversal of 12151621 is 12615121.

12151621 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 1718721 + 10432900 = 1311^2 + 3230^2 .

It is not a de Polignac number, because 12151621 - 2¹³ = 12143429 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12151661) 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 11 ways as a sum of consecutive naturals, for example, 14391 + ... + 15211.

It is an arithmetic number, because the mean of its divisors is an integer number (1096137).

Almost surely, 2^12151621 is an apocalyptic number.

It is an amenable number.

12151621 is a deficient number, since it is larger than the sum of its proper divisors (1002023).

12151621 is an equidigital number, since it uses as much as digits as its factorization.

12151621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 900 (or 881 counting only the distinct ones).

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

The square root of 12151621 is about 3485.9175262763. The cubic root of 12151621 is about 229.9030530296.

Adding to 12151621 its reverse (12615121), we get a palindrome (24766742).

The spelling of 12151621 in words is "twelve million, one hundred fifty-one thousand, six hundred twenty-one".