16720105 has 4 divisors (see below), whose sum is σ = 20064132. Its totient is φ = 13376080.

The previous prime is 16720097. The next prime is 16720111. The reversal of 16720105 is 50102761.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 50102761 = 1877 ⋅26693.

It can be written as a sum of positive squares in 2 ways, for example, as 3968064 + 12752041 = 1992^2 + 3571^2 .

It is not a de Polignac number, because 16720105 - 2³ = 16720097 is a prime.

It is a super-2 number, since 2×16720105² = 559123822422050, which contains 22 as substring.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1672006 + ... + 1672015.

It is an arithmetic number, because the mean of its divisors is an integer number (5016033).

Almost surely, 2^16720105 is an apocalyptic number.

It is an amenable number.

16720105 is a deficient number, since it is larger than the sum of its proper divisors (3344027).

16720105 is an equidigital number, since it uses as much as digits as its factorization.

16720105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3344026.

The product of its (nonzero) digits is 420, while the sum is 22.

The square root of 16720105 is about 4089.0224993267. The cubic root of 16720105 is about 255.7091882003.

Adding to 16720105 its reverse (50102761), we get a palindrome (66822866).

The spelling of 16720105 in words is "sixteen million, seven hundred twenty thousand, one hundred five".