2161831817 has 8 divisors (see below), whose sum is σ = 2177710080. Its totient is φ = 2145974400.

The previous prime is 2161831811. The next prime is 2161831853. The reversal of 2161831817 is 7181381612.

It is a happy number.

2161831817 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 2161831817 - 2²² = 2157637513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2161831811) 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, 246809 + ... + 255417.

It is an arithmetic number, because the mean of its divisors is an integer number (272213760).

Almost surely, 2^2161831817 is an apocalyptic number.

It is an amenable number.

2161831817 is a deficient number, since it is larger than the sum of its proper divisors (15878263).

2161831817 is a wasteful number, since it uses less digits than its factorization.

2161831817 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10423.

The product of its digits is 16128, while the sum is 38.

The square root of 2161831817 is about 46495.5031911689. The cubic root of 2161831817 is about 1293.0261302210.

It can be divided in two parts, 21618 and 31817, that added together give a palindrome (53435).

The spelling of 2161831817 in words is "two billion, one hundred sixty-one million, eight hundred thirty-one thousand, eight hundred seventeen".