13843721 has 4 divisors (see below), whose sum is σ = 14165712. Its totient is φ = 13521732.

The previous prime is 13843717. The next prime is 13843751. The reversal of 13843721 is 12734831.

13843721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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: 12734831 = 31 ⋅410801.

It is a cyclic number.

It is not a de Polignac number, because 13843721 - 2² = 13843717 is a prime.

It is a super-2 number, since 2×13843721² = 383297222251682, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13843751) 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, 160931 + ... + 161016.

It is an arithmetic number, because the mean of its divisors is an integer number (3541428).

Almost surely, 2^13843721 is an apocalyptic number.

It is an amenable number.

13843721 is a deficient number, since it is larger than the sum of its proper divisors (321991).

13843721 is an equidigital number, since it uses as much as digits as its factorization.

13843721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 321990.

The product of its digits is 4032, while the sum is 29.

The square root of 13843721 is about 3720.7151194360. The cubic root of 13843721 is about 240.1140719305.

The spelling of 13843721 in words is "thirteen million, eight hundred forty-three thousand, seven hundred twenty-one".