9872161 has 4 divisors (see below), whose sum is σ = 10631572. Its totient is φ = 9112752.

The previous prime is 9872131. The next prime is 9872171. The reversal of 9872161 is 1612789.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1612789 = 73 ⋅22093.

It can be written as a sum of positive squares in 2 ways, for example, as 4494400 + 5377761 = 2120^2 + 2319^2 .

It is a cyclic number.

It is not a de Polignac number, because 9872161 - 2⁹ = 9871649 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9872111) 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, 379686 + ... + 379711.

It is an arithmetic number, because the mean of its divisors is an integer number (2657893).

Almost surely, 2^9872161 is an apocalyptic number.

It is an amenable number.

9872161 is a deficient number, since it is larger than the sum of its proper divisors (759411).

9872161 is a wasteful number, since it uses less digits than its factorization.

9872161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 759410.

The product of its digits is 6048, while the sum is 34.

The square root of 9872161 is about 3141.9995225970. Note that the first 3 decimals coincide. The cubic root of 9872161 is about 214.5214595563.

The spelling of 9872161 in words is "nine million, eight hundred seventy-two thousand, one hundred sixty-one".