13416721 has 4 divisors (see below), whose sum is σ = 13433200. Its totient is φ = 13400244.

The previous prime is 13416719. The next prime is 13416727. The reversal of 13416721 is 12761431.

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: 12761431 = 157 ⋅81283.

It is a cyclic number.

It is not a de Polignac number, because 13416721 - 2¹ = 13416719 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 16.

It is not an unprimeable number, because it can be changed into a prime (13416727) 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, 6951 + ... + 8668.

It is an arithmetic number, because the mean of its divisors is an integer number (3358300).

Almost surely, 2^13416721 is an apocalyptic number.

It is an amenable number.

13416721 is a deficient number, since it is larger than the sum of its proper divisors (16479).

13416721 is an equidigital number, since it uses as much as digits as its factorization.

13416721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16478.

The product of its digits is 1008, while the sum is 25.

The square root of 13416721 is about 3662.8842460553. The cubic root of 13416721 is about 237.6195283843.

The spelling of 13416721 in words is "thirteen million, four hundred sixteen thousand, seven hundred twenty-one".