16121217 has 8 divisors (see below), whose sum is σ = 24565696. Its totient is φ = 9212112.

The previous prime is 16121207. The next prime is 16121221. The reversal of 16121217 is 71212161.

It is a happy number.

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

It is not a de Polignac number, because 16121217 - 2⁷ = 16121089 is a prime.

It is a super-2 number, since 2×16121217² = 519787275122178, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21), and also a Moran number because the ratio is a prime number: 767677 = 16121217 / (1 + 6 + 1 + 2 + 1 + 2 + 1 + 7).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 16121193 and 16121202.

It is not an unprimeable number, because it can be changed into a prime (16121207) 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, 383818 + ... + 383859.

It is an arithmetic number, because the mean of its divisors is an integer number (3070712).

Almost surely, 2^16121217 is an apocalyptic number.

It is an amenable number.

16121217 is a deficient number, since it is larger than the sum of its proper divisors (8444479).

16121217 is an equidigital number, since it uses as much as digits as its factorization.

16121217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 767687.

The product of its digits is 168, while the sum is 21.

The square root of 16121217 is about 4015.1235348368. The cubic root of 16121217 is about 252.6189590758.

Adding to 16121217 its reverse (71212161), we get a palindrome (87333378).

The spelling of 16121217 in words is "sixteen million, one hundred twenty-one thousand, two hundred seventeen".