13000021 has 4 divisors (see below), whose sum is σ = 13007500. Its totient is φ = 12992544.

The previous prime is 12999997. The next prime is 13000027. The reversal of 13000021 is 12000031.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 12000031 = 1553 ⋅7727.

It can be written as a sum of positive squares in 2 ways, for example, as 784996 + 12215025 = 886^2 + 3495^2 .

It is a cyclic number.

It is not a de Polignac number, because 13000021 - 2⁵ = 12999989 is a prime.

It is a Duffinian number.

13000021 is a modest number, since divided by 21 gives 13 as remainder.

It is a junction number, because it is equal to n+sod(n) for n = 12999968 and 13000013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13000027) 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 3 ways as a sum of consecutive naturals, for example, 385 + ... + 5113.

It is an arithmetic number, because the mean of its divisors is an integer number (3251875).

Almost surely, 2^13000021 is an apocalyptic number.

It is an amenable number.

13000021 is a deficient number, since it is larger than the sum of its proper divisors (7479).

13000021 is an equidigital number, since it uses as much as digits as its factorization.

13000021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7478.

The product of its (nonzero) digits is 6, while the sum is 7.

The square root of 13000021 is about 3605.5541876388. The cubic root of 13000021 is about 235.1335953823.

Adding to 13000021 its reverse (12000031), we get a palindrome (25000052).

The spelling of 13000021 in words is "thirteen million, twenty-one", and thus it is an aban number and an uban number.