13280821 has 4 divisors (see below), whose sum is σ = 13858272. Its totient is φ = 12703372.

The previous prime is 13280819. The next prime is 13280831. The reversal of 13280821 is 12808231.

13280821 is digitally balanced in base 2, 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 Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12808231 = 61 ⋅209971.

It is a cyclic number.

It is not a de Polignac number, because 13280821 - 2¹ = 13280819 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 (13280831) 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, 288691 + ... + 288736.

It is an arithmetic number, because the mean of its divisors is an integer number (3464568).

Almost surely, 2^13280821 is an apocalyptic number.

It is an amenable number.

13280821 is a deficient number, since it is larger than the sum of its proper divisors (577451).

13280821 is an equidigital number, since it uses as much as digits as its factorization.

13280821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 577450.

The product of its (nonzero) digits is 768, while the sum is 25.

The square root of 13280821 is about 3644.2860754886. The cubic root of 13280821 is about 236.8145094458.

The spelling of 13280821 in words is "thirteen million, two hundred eighty thousand, eight hundred twenty-one".