13021257 has 4 divisors (see below), whose sum is σ = 17361680. Its totient is φ = 8680836.

The previous prime is 13021247. The next prime is 13021273. The reversal of 13021257 is 75212031.

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 not a de Polignac number, because 13021257 - 2¹⁰ = 13020233 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13021207) 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, 2170207 + ... + 2170212.

It is an arithmetic number, because the mean of its divisors is an integer number (4340420).

Almost surely, 2^13021257 is an apocalyptic number.

It is an amenable number.

13021257 is a deficient number, since it is larger than the sum of its proper divisors (4340423).

13021257 is an equidigital number, since it uses as much as digits as its factorization.

13021257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4340422.

The product of its (nonzero) digits is 420, while the sum is 21.

The square root of 13021257 is about 3608.4978869330. The cubic root of 13021257 is about 235.2615587804.

Adding to 13021257 its reverse (75212031), we get a palindrome (88233288).

The spelling of 13021257 in words is "thirteen million, twenty-one thousand, two hundred fifty-seven".