13451721 has 4 divisors (see below), whose sum is σ = 17935632. Its totient is φ = 8967812.

The previous prime is 13451707. The next prime is 13451741. The reversal of 13451721 is 12715431.

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 a cyclic number.

It is not a de Polignac number, because 13451721 - 2⁹ = 13451209 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 13451691 and 13451700.

It is not an unprimeable number, because it can be changed into a prime (13451741) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2241951 + ... + 2241956.

It is an arithmetic number, because the mean of its divisors is an integer number (4483908).

Almost surely, 2^13451721 is an apocalyptic number.

It is an amenable number.

13451721 is a deficient number, since it is larger than the sum of its proper divisors (4483911).

13451721 is an equidigital number, since it uses as much as digits as its factorization.

13451721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4483910.

The product of its digits is 840, while the sum is 24.

The square root of 13451721 is about 3667.6587900185. The cubic root of 13451721 is about 237.8259738113.

The spelling of 13451721 in words is "thirteen million, four hundred fifty-one thousand, seven hundred twenty-one".