2161816929 has 12 divisors (see below), whose sum is σ = 3124660500. Its totient is φ = 1440271584.

The previous prime is 2161816927. The next prime is 2161816949. The reversal of 2161816929 is 9296181612.

2161816929 is a `hidden beast` number, since 2 + 1 + 618 + 1 + 6 + 9 + 29 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 878529600 + 1283287329 = 29640^2 + 35823^2 .

It is not a de Polignac number, because 2161816929 - 2¹ = 2161816927 is a prime.

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

It is not an unprimeable number, because it can be changed into a prime (2161816927) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 63594 + ... + 91475.

It is an arithmetic number, because the mean of its divisors is an integer number (260388375).

Almost surely, 2^2161816929 is an apocalyptic number.

It is an amenable number.

2161816929 is a deficient number, since it is larger than the sum of its proper divisors (962843571).

2161816929 is a wasteful number, since it uses less digits than its factorization.

2161816929 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 156624 (or 156621 counting only the distinct ones).

The product of its digits is 93312, while the sum is 45.

The square root of 2161816929 is about 46495.3430893891. The cubic root of 2161816929 is about 1293.0231619640.

The spelling of 2161816929 in words is "two billion, one hundred sixty-one million, eight hundred sixteen thousand, nine hundred twenty-nine".