16120721 has 8 divisors (see below), whose sum is σ = 17146080. Its totient is φ = 15113088.

The previous prime is 16120697. The next prime is 16120733. The reversal of 16120721 is 12702161.

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 16120721 - 2¹⁴ = 16104337 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 16120693 and 16120702.

It is not an unprimeable number, because it can be changed into a prime (16120771) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2531 + ... + 6216.

It is an arithmetic number, because the mean of its divisors is an integer number (2143260).

Almost surely, 2^16120721 is an apocalyptic number.

It is an amenable number.

16120721 is a deficient number, since it is larger than the sum of its proper divisors (1025359).

16120721 is an equidigital number, since it uses as much as digits as its factorization.

16120721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8863.

The product of its (nonzero) digits is 168, while the sum is 20.

The square root of 16120721 is about 4015.0617678935. The cubic root of 16120721 is about 252.6163682812.

Adding to 16120721 its reverse (12702161), we get a palindrome (28822882).

The spelling of 16120721 in words is "sixteen million, one hundred twenty thousand, seven hundred twenty-one".