13271721 has 4 divisors (see below), whose sum is σ = 17695632. Its totient is φ = 8847812.

The previous prime is 13271711. The next prime is 13271723. The reversal of 13271721 is 12717231.

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: 12717231 = 3 ⋅4239077.

It is a cyclic number.

It is not a de Polignac number, because 13271721 - 2⁷ = 13271593 is a prime.

It is a super-2 number, since 2×13271721² = 352277156603682, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 13271691 and 13271700.

It is not an unprimeable number, because it can be changed into a prime (13271723) 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, 2211951 + ... + 2211956.

It is an arithmetic number, because the mean of its divisors is an integer number (4423908).

Almost surely, 2^13271721 is an apocalyptic number.

It is an amenable number.

13271721 is a deficient number, since it is larger than the sum of its proper divisors (4423911).

13271721 is an equidigital number, since it uses as much as digits as its factorization.

13271721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4423910.

The product of its digits is 588, while the sum is 24.

The square root of 13271721 is about 3643.0373316781. The cubic root of 13271721 is about 236.7604087637.

Adding to 13271721 its reverse (12717231), we get a palindrome (25988952).

The spelling of 13271721 in words is "thirteen million, two hundred seventy-one thousand, seven hundred twenty-one".