2165148981 has 8 divisors (see below), whose sum is σ = 3207628160. Its totient is φ = 1443432636.

The previous prime is 2165148977. The next prime is 2165148983. The reversal of 2165148981 is 1898415612.

It is a happy number.

2165148981 is a `hidden beast` number, since 2 + 165 + 1 + 489 + 8 + 1 = 666.

It is not a de Polignac number, because 2165148981 - 2² = 2165148977 is a prime.

It is a super-2 number, since 2×2165148981² = 9375740219850676722, 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 (2165148983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 40095325 + ... + 40095378.

It is an arithmetic number, because the mean of its divisors is an integer number (400953520).

Almost surely, 2^2165148981 is an apocalyptic number.

It is an amenable number.

2165148981 is a deficient number, since it is larger than the sum of its proper divisors (1042479179).

2165148981 is an equidigital number, since it uses as much as digits as its factorization.

2165148981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80190712 (or 80190706 counting only the distinct ones).

The product of its digits is 138240, while the sum is 45.

The square root of 2165148981 is about 46531.1613974979. The cubic root of 2165148981 is about 1293.6871418315.

The spelling of 2165148981 in words is "two billion, one hundred sixty-five million, one hundred forty-eight thousand, nine hundred eighty-one".