2171881170981 has 6 divisors (see below), whose sum is σ = 3137161691430. Its totient is φ = 1447920780648.

The previous prime is 2171881170931. The next prime is 2171881171063. The reversal of 2171881170981 is 1890711881712.

2171881170981 is a `hidden beast` number, since 217 + 188 + 1 + 170 + 9 + 81 = 666.

It can be written as a sum of positive squares in only one way, i.e., 2159109910881 + 12771260100 = 1469391^2 + 113010^2 .

It is not a de Polignac number, because 2171881170981 - 2³⁰ = 2170807429157 is a prime.

It is a super-2 number, since 2×2171881170981² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2171881170931) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 120660065046 + ... + 120660065063.

It is an arithmetic number, because the mean of its divisors is an integer number (522860281905).

Almost surely, 2^{2171881170981} is an apocalyptic number.

It is an amenable number.

2171881170981 is a deficient number, since it is larger than the sum of its proper divisors (965280520449).

2171881170981 is a wasteful number, since it uses less digits than its factorization.

2171881170981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 241320130115 (or 241320130112 counting only the distinct ones).

The product of its (nonzero) digits is 451584, while the sum is 54.

The spelling of 2171881170981 in words is "two trillion, one hundred seventy-one billion, eight hundred eighty-one million, one hundred seventy thousand, nine hundred eighty-one".