16104721 has 2 divisors, whose sum is σ = 16104722. Its totient is φ = 16104720.

The previous prime is 16104719. The next prime is 16104733. The reversal of 16104721 is 12740161.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15563025 + 541696 = 3945^2 + 736^2 .

It is a cyclic number.

It is not a de Polignac number, because 16104721 - 2¹ = 16104719 is a prime.

Together with 16104719, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 16104692 and 16104701.

It is not a weakly prime, because it can be changed into another prime (16104701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8052360 + 8052361.

It is an arithmetic number, because the mean of its divisors is an integer number (8052361).

Almost surely, 2^16104721 is an apocalyptic number.

It is an amenable number.

16104721 is a deficient number, since it is larger than the sum of its proper divisors (1).

16104721 is an equidigital number, since it uses as much as digits as its factorization.

16104721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 336, while the sum is 22.

The square root of 16104721 is about 4013.0687758871. The cubic root of 16104721 is about 252.5327657378.

Adding to 16104721 its reverse (12740161), we get a palindrome (28844882).

The spelling of 16104721 in words is "sixteen million, one hundred four thousand, seven hundred twenty-one".