13127921 has 4 divisors (see below), whose sum is σ = 13169652. Its totient is φ = 13086192.

The previous prime is 13127887. The next prime is 13127929. The reversal of 13127921 is 12972131.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 5085025 + 8042896 = 2255^2 + 2836^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-13127921 is a prime.

It is a super-3 number, since 3×13127921³ (a number of 22 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13127929) 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, 20390 + ... + 21023.

It is an arithmetic number, because the mean of its divisors is an integer number (3292413).

Almost surely, 2^13127921 is an apocalyptic number.

It is an amenable number.

13127921 is a deficient number, since it is larger than the sum of its proper divisors (41731).

13127921 is an equidigital number, since it uses as much as digits as its factorization.

13127921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41730.

The product of its digits is 756, while the sum is 26.

The square root of 13127921 is about 3623.2473004199. The cubic root of 13127921 is about 235.9021966183.

The spelling of 13127921 in words is "thirteen million, one hundred twenty-seven thousand, nine hundred twenty-one".