13771721 has 4 divisors (see below), whose sum is σ = 14005200. Its totient is φ = 13538244.

The previous prime is 13771711. The next prime is 13771727. The reversal of 13771721 is 12717731.

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: 12717731 = 13 ⋅978287.

It is a cyclic number.

It is not a de Polignac number, because 13771721 - 2¹⁴ = 13755337 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13771727) 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, 116651 + ... + 116768.

It is an arithmetic number, because the mean of its divisors is an integer number (3501300).

Almost surely, 2^13771721 is an apocalyptic number.

It is an amenable number.

13771721 is a deficient number, since it is larger than the sum of its proper divisors (233479).

13771721 is an equidigital number, since it uses as much as digits as its factorization.

13771721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 233478.

The product of its digits is 2058, while the sum is 29.

The square root of 13771721 is about 3711.0269468167. The cubic root of 13771721 is about 239.6970773093.

The spelling of 13771721 in words is "thirteen million, seven hundred seventy-one thousand, seven hundred twenty-one".