12555021 has 4 divisors (see below), whose sum is σ = 16740032. Its totient is φ = 8370012.

The previous prime is 12554981. The next prime is 12555041. The reversal of 12555021 is 12055521.

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: 12055521 = 3 ⋅4018507.

It is not a de Polignac number, because 12555021 - 2⁶ = 12554957 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12555041) 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, 2092501 + ... + 2092506.

It is an arithmetic number, because the mean of its divisors is an integer number (4185008).

Almost surely, 2^12555021 is an apocalyptic number.

It is an amenable number.

12555021 is a deficient number, since it is larger than the sum of its proper divisors (4185011).

12555021 is an equidigital number, since it uses as much as digits as its factorization.

12555021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4185010.

The product of its (nonzero) digits is 500, while the sum is 21.

The square root of 12555021 is about 3543.3065066404. The cubic root of 12555021 is about 232.4194564345.

Adding to 12555021 its product of nonzero digits (500), we get a palindrome (12555521).

Subtracting from 12555021 its reverse (12055521), we obtain a triangular number (499500 = T₉₉₉).

The spelling of 12555021 in words is "twelve million, five hundred fifty-five thousand, twenty-one".