2161948181 has 8 divisors (see below), whose sum is σ = 2257727040. Its totient is φ = 2066317792.

The previous prime is 2161948141. The next prime is 2161948213. The reversal of 2161948181 is 1818491612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-2161948181 is a prime.

It is a super-2 number, since 2×2161948181² = 9348039874658417522, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2161948121) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6815 + ... + 66108.

It is an arithmetic number, because the mean of its divisors is an integer number (282215880).

Almost surely, 2^2161948181 is an apocalyptic number.

It is an amenable number.

2161948181 is a deficient number, since it is larger than the sum of its proper divisors (95778859).

2161948181 is a wasteful number, since it uses less digits than its factorization.

2161948181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74235.

The product of its digits is 27648, while the sum is 41.

The square root of 2161948181 is about 46496.7545211491. The cubic root of 2161948181 is about 1293.0493295269.

The spelling of 2161948181 in words is "two billion, one hundred sixty-one million, nine hundred forty-eight thousand, one hundred eighty-one".