13004021 has 4 divisors (see below), whose sum is σ = 13015200. Its totient is φ = 12992844.

The previous prime is 13003987. The next prime is 13004051. The reversal of 13004021 is 12040031.

It is a happy number.

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 a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 12040031 = 109 ⋅110459.

It is a cyclic number.

It is not a de Polignac number, because 13004021 - 2⁶ = 13003957 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 13003993 and 13004011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13004051) 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, 3611 + ... + 6248.

It is an arithmetic number, because the mean of its divisors is an integer number (3253800).

Almost surely, 2^13004021 is an apocalyptic number.

It is an amenable number.

13004021 is a deficient number, since it is larger than the sum of its proper divisors (11179).

13004021 is an equidigital number, since it uses as much as digits as its factorization.

13004021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11178.

The product of its (nonzero) digits is 24, while the sum is 11.

The square root of 13004021 is about 3606.1088447245. The cubic root of 13004021 is about 235.1577091365.

Adding to 13004021 its reverse (12040031), we get a palindrome (25044052).

The spelling of 13004021 in words is "thirteen million, four thousand, twenty-one".