2115722581 has 16 divisors (see below), whose sum is σ = 2446174080. Its totient is φ = 1792373760.

The previous prime is 2115722569. The next prime is 2115722603. The reversal of 2115722581 is 1852275112.

It is not a de Polignac number, because 2115722581 - 2¹⁵ = 2115689813 is a prime.

It is a super-2 number, since 2×2115722581² = 8952564079506603122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2115722881) 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 15 ways as a sum of consecutive naturals, for example, 657705 + ... + 660913.

It is an arithmetic number, because the mean of its divisors is an integer number (152885880).

Almost surely, 2^2115722581 is an apocalyptic number.

It is an amenable number.

2115722581 is a deficient number, since it is larger than the sum of its proper divisors (330451499).

2115722581 is an equidigital number, since it uses as much as digits as its factorization.

2115722581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4284.

The product of its digits is 11200, while the sum is 34.

The square root of 2115722581 is about 45996.9844772459. The cubic root of 2115722581 is about 1283.7670967675.

Adding to 2115722581 its reverse (1852275112), we get a palindrome (3967997693).

The spelling of 2115722581 in words is "two billion, one hundred fifteen million, seven hundred twenty-two thousand, five hundred eighty-one".