13612721 has 4 divisors (see below), whose sum is σ = 14329200. Its totient is φ = 12896244.

The previous prime is 13612717. The next prime is 13612741. The reversal of 13612721 is 12721631.

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 13612721 - 2² = 13612717 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13612741) 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, 358211 + ... + 358248.

It is an arithmetic number, because the mean of its divisors is an integer number (3582300).

Almost surely, 2^13612721 is an apocalyptic number.

It is an amenable number.

13612721 is a deficient number, since it is larger than the sum of its proper divisors (716479).

13612721 is an equidigital number, since it uses as much as digits as its factorization.

13612721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 716478.

The product of its digits is 504, while the sum is 23.

The square root of 13612721 is about 3689.5421125121. The cubic root of 13612721 is about 238.7710382309.

It can be divided in two parts, 1361 and 2721, that multiplied together give a triangular number (3703281 = T₂₇₂₁).

The spelling of 13612721 in words is "thirteen million, six hundred twelve thousand, seven hundred twenty-one".