2171822981 has 8 divisors (see below), whose sum is σ = 2338554240. Its totient is φ = 2009422528.

The previous prime is 2171822941. The next prime is 2171822993. The reversal of 2171822981 is 1892281712.

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

It is a cyclic number.

It is not a de Polignac number, because 2171822981 - 2²² = 2167628677 is a prime.

It is a super-2 number, since 2×2171822981² = 9433630121599452722, 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 (2171822941) 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, 1081661 + ... + 1083666.

It is an arithmetic number, because the mean of its divisors is an integer number (292319280).

Almost surely, 2^2171822981 is an apocalyptic number.

It is an amenable number.

2171822981 is a deficient number, since it is larger than the sum of its proper divisors (166731259).

2171822981 is a wasteful number, since it uses less digits than its factorization.

2171822981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2165403.

The product of its digits is 32256, while the sum is 41.

The square root of 2171822981 is about 46602.8215991264. The cubic root of 2171822981 is about 1295.0150276278.

The spelling of 2171822981 in words is "two billion, one hundred seventy-one million, eight hundred twenty-two thousand, nine hundred eighty-one".