16851421197 has 40 divisors (see below), whose sum is σ = 27125744184. Its totient is φ = 10363894272.

The previous prime is 16851421187. The next prime is 16851421211. The reversal of 16851421197 is 79112415861.

16851421197 is a `hidden beast` number, since 16 + 8 + 514 + 2 + 119 + 7 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 1739390436 + 15112030761 = 41706^2 + 122931^2 .

It is not a de Polignac number, because 16851421197 - 2⁶ = 16851421133 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16851421177) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 2263393 + ... + 2270825.

Almost surely, 2^16851421197 is an apocalyptic number.

It is an amenable number.

16851421197 is a deficient number, since it is larger than the sum of its proper divisors (10274322987).

16851421197 is a wasteful number, since it uses less digits than its factorization.

16851421197 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9611 (or 9602 counting only the distinct ones).

The product of its digits is 120960, while the sum is 45.

The spelling of 16851421197 in words is "sixteen billion, eight hundred fifty-one million, four hundred twenty-one thousand, one hundred ninety-seven".