12500021 has 4 divisors (see below), whose sum is σ = 12535200. Its totient is φ = 12464844.

The previous prime is 12500003. The next prime is 12500029. The reversal of 12500021 is 12000521.

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 12500021 - 2¹⁴ = 12483637 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12499975 and 12500011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12500029) 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, 17051 + ... + 17768.

It is an arithmetic number, because the mean of its divisors is an integer number (3133800).

Almost surely, 2^12500021 is an apocalyptic number.

It is an amenable number.

12500021 is a deficient number, since it is larger than the sum of its proper divisors (35179).

12500021 is an equidigital number, since it uses as much as digits as its factorization.

12500021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35178.

The product of its (nonzero) digits is 20, while the sum is 11.

The square root of 12500021 is about 3535.5368757800. The cubic root of 12500021 is about 232.0795716451.

Adding to 12500021 its reverse (12000521), we get a palindrome (24500542).

Subtracting from 12500021 its reverse (12000521), we obtain a triangular number (499500 = T₉₉₉).

The spelling of 12500021 in words is "twelve million, five hundred thousand, twenty-one".