13247021 has 4 divisors (see below), whose sum is σ = 13254972. Its totient is φ = 13239072.

The previous prime is 13246991. The next prime is 13247023. The reversal of 13247021 is 12074231.

13247021 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

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: 12074231 = 13 ⋅928787.

It can be written as a sum of positive squares in 2 ways, for example, as 2449225 + 10797796 = 1565^2 + 3286^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-13247021 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 = 13246984 and 13247002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13247023) 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, 410 + ... + 5163.

It is an arithmetic number, because the mean of its divisors is an integer number (3313743).

Almost surely, 2^13247021 is an apocalyptic number.

It is an amenable number.

13247021 is a deficient number, since it is larger than the sum of its proper divisors (7951).

13247021 is an equidigital number, since it uses as much as digits as its factorization.

13247021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7950.

The product of its (nonzero) digits is 336, while the sum is 20.

The square root of 13247021 is about 3639.6457245177. The cubic root of 13247021 is about 236.6134392851.

The spelling of 13247021 in words is "thirteen million, two hundred forty-seven thousand, twenty-one".