16086721 has 4 divisors (see below), whose sum is σ = 18384832. Its totient is φ = 13788612.

The previous prime is 16086713. The next prime is 16086731. The reversal of 16086721 is 12768061.

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: 12768061 = 293 ⋅43577.

It is a cyclic number.

It is not a de Polignac number, because 16086721 - 2³ = 16086713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16086731) 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, 1149045 + ... + 1149058.

It is an arithmetic number, because the mean of its divisors is an integer number (4596208).

Almost surely, 2^16086721 is an apocalyptic number.

It is an amenable number.

16086721 is a deficient number, since it is larger than the sum of its proper divisors (2298111).

16086721 is an equidigital number, since it uses as much as digits as its factorization.

16086721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2298110.

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 16086721 is about 4010.8254761333. The cubic root of 16086721 is about 252.4386466625.

It can be divided in two parts, 16086 and 721, that added together give a 5-th power (16807 = 7⁵).

The spelling of 16086721 in words is "sixteen million, eighty-six thousand, seven hundred twenty-one".