16122721 has 8 divisors (see below), whose sum is σ = 16585184. Its totient is φ = 15664320.

The previous prime is 16122703. The next prime is 16122737. The reversal of 16122721 is 12722161.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 16122721 - 2¹¹ = 16120673 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 16122692 and 16122701.

It is not an unprimeable number, because it can be changed into a prime (16122761) 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 7 ways as a sum of consecutive naturals, for example, 8185 + ... + 9961.

It is an arithmetic number, because the mean of its divisors is an integer number (2073148).

Almost surely, 2^16122721 is an apocalyptic number.

It is an amenable number.

16122721 is a deficient number, since it is larger than the sum of its proper divisors (462463).

16122721 is a wasteful number, since it uses less digits than its factorization.

16122721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2031.

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

The square root of 16122721 is about 4015.3108223399. The cubic root of 16122721 is about 252.6268147090.

Adding to 16122721 its reverse (12722161), we get a palindrome (28844882).

The spelling of 16122721 in words is "sixteen million, one hundred twenty-two thousand, seven hundred twenty-one".