12251621 has 4 divisors (see below), whose sum is σ = 12325152. Its totient is φ = 12178092.

The previous prime is 12251609. The next prime is 12251623. The reversal of 12251621 is 12615221.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12615221 = 19 ⋅663959.

It is a cyclic number.

It is not a de Polignac number, because 12251621 - 2¹⁸ = 11989477 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12251593 and 12251602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12251623) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 36515 + ... + 36848.

It is an arithmetic number, because the mean of its divisors is an integer number (3081288).

Almost surely, 2^12251621 is an apocalyptic number.

It is an amenable number.

12251621 is a deficient number, since it is larger than the sum of its proper divisors (73531).

12251621 is an equidigital number, since it uses as much as digits as its factorization.

12251621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73530.

The product of its digits is 240, while the sum is 20.

The square root of 12251621 is about 3500.2315637683. The cubic root of 12251621 is about 230.5319822051.

Adding to 12251621 its reverse (12615221), we get a palindrome (24866842).

The spelling of 12251621 in words is "twelve million, two hundred fifty-one thousand, six hundred twenty-one".