2115172081 has 27 divisors (see below), whose sum is σ = 2410808673. Its totient is φ = 1854357120.

The previous prime is 2115172063. The next prime is 2115172097. The reversal of 2115172081 is 1802715112.

The square root of 2115172081 is 45991.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 81162081 + 2034010000 = 9009^2 + 45100^2 .

It is not a de Polignac number, because 2115172081 - 2⁵ = 2115172049 is a prime.

It is a super-2 number, since 2×2115172081² = 8947905864483741122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2115172061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 18718281 + ... + 18718393.

Almost surely, 2^2115172081 is an apocalyptic number.

2115172081 is the 45991-st square number.

2115172081 is the 22996-th centered octagonal number.

It is an amenable number.

2115172081 is a deficient number, since it is larger than the sum of its proper divisors (295636592).

2115172081 is an equidigital number, since it uses as much as digits as its factorization.

2115172081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 322 (or 161 counting only the distinct ones).

The product of its (nonzero) digits is 1120, while the sum is 28.

The cubic root of 2115172081 is about 1283.6557439376.

Adding to 2115172081 its reverse (1802715112), we get a palindrome (3917887193).

The spelling of 2115172081 in words is "two billion, one hundred fifteen million, one hundred seventy-two thousand, eighty-one".