12655621 has 4 divisors (see below), whose sum is σ = 13806144. Its totient is φ = 11505100.

The previous prime is 12655619. The next prime is 12655637.

12655621 is nontrivially palindromic in base 10.

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.

It is a cyclic number.

It is not a de Polignac number, because 12655621 - 2¹ = 12655619 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 12655621.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12655651) 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, 575245 + ... + 575266.

It is an arithmetic number, because the mean of its divisors is an integer number (3451536).

Almost surely, 2^12655621 is an apocalyptic number.

12655621 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

12655621 is a deficient number, since it is larger than the sum of its proper divisors (1150523).

12655621 is a wasteful number, since it uses less digits than its factorization.

12655621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1150522.

The product of its digits is 3600, while the sum is 28.

The square root of 12655621 is about 3557.4739633622. The cubic root of 12655621 is about 233.0385772421.

It can be divided in two parts, 1265 and 5621, that added together give a palindrome (6886).

The spelling of 12655621 in words is "twelve million, six hundred fifty-five thousand, six hundred twenty-one".