2160261581 has 4 divisors (see below), whose sum is σ = 2169225564. Its totient is φ = 2151297600.

The previous prime is 2160261569. The next prime is 2160261599. The reversal of 2160261581 is 1851620612.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1856317225 + 303944356 = 43085^2 + 17434^2 .

It is a cyclic number.

It is not a de Polignac number, because 2160261581 - 2²⁶ = 2093152717 is a prime.

It is a super-2 number, since 2×2160261581² = 9333460196689239122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2160261541) 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, 4481630 + ... + 4482111.

It is an arithmetic number, because the mean of its divisors is an integer number (542306391).

Almost surely, 2^2160261581 is an apocalyptic number.

It is an amenable number.

2160261581 is a deficient number, since it is larger than the sum of its proper divisors (8963983).

2160261581 is an equidigital number, since it uses as much as digits as its factorization.

2160261581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8963982.

The product of its (nonzero) digits is 5760, while the sum is 32.

The square root of 2160261581 is about 46478.6142327845. The cubic root of 2160261581 is about 1292.7129933185.

The spelling of 2160261581 in words is "two billion, one hundred sixty million, two hundred sixty-one thousand, five hundred eighty-one".