16855997 has 4 divisors (see below), whose sum is σ = 16913820. Its totient is φ = 16798176.

The previous prime is 16855967. The next prime is 16855999. The reversal of 16855997 is 79955861.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 15202201 + 1653796 = 3899^2 + 1286^2 .

It is a cyclic number.

It is not a de Polignac number, because 16855997 - 2²⁴ = 78781 is a prime.

It is a super-3 number, since 3×16855997³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16855999) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28472 + ... + 29057.

It is an arithmetic number, because the mean of its divisors is an integer number (4228455).

Almost surely, 2^16855997 is an apocalyptic number.

It is an amenable number.

16855997 is a deficient number, since it is larger than the sum of its proper divisors (57823).

16855997 is an equidigital number, since it uses as much as digits as its factorization.

16855997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57822.

The product of its digits is 680400, while the sum is 50.

The square root of 16855997 is about 4105.6055582581. The cubic root of 16855997 is about 256.4000753259.

It can be divided in two parts, 168 and 55997, that added together give a palindrome (56165).

The spelling of 16855997 in words is "sixteen million, eight hundred fifty-five thousand, nine hundred ninety-seven".