2172115816 has 32 divisors (see below), whose sum is σ = 4457917800. Its totient is φ = 986077440.

The previous prime is 2172115811. The next prime is 2172115817. The reversal of 2172115816 is 6185112712.

It can be written as a sum of positive squares in 4 ways, for example, as 1513988100 + 658127716 = 38910^2 + 25654^2 .

It is not an unprimeable number, because it can be changed into a prime (2172115811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 164851 + ... + 177538.

Almost surely, 2^2172115816 is an apocalyptic number.

2172115816 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

2172115816 is an abundant number, since it is smaller than the sum of its proper divisors (2285801984).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2172115816 is a wasteful number, since it uses less digits than its factorization.

2172115816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 342469 (or 342465 counting only the distinct ones).

The product of its digits is 6720, while the sum is 34.

The square root of 2172115816 is about 46605.9633094307. The cubic root of 2172115816 is about 1295.0732289156.

The spelling of 2172115816 in words is "two billion, one hundred seventy-two million, one hundred fifteen thousand, eight hundred sixteen".