2171946981 has 8 divisors (see below), whose sum is σ = 3048346720. Its totient is φ = 1371755952.

The previous prime is 2171946977. The next prime is 2171946983. The reversal of 2171946981 is 1896491712.

2171946981 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 2171946981 - 2² = 2171946977 is a prime.

It is a super-2 number, since 2×2171946981² = 9434707376550028722, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2171946981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2171946983) 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, 19052110 + ... + 19052223.

It is an arithmetic number, because the mean of its divisors is an integer number (381043340).

Almost surely, 2^2171946981 is an apocalyptic number.

It is an amenable number.

2171946981 is a deficient number, since it is larger than the sum of its proper divisors (876399739).

2171946981 is a wasteful number, since it uses less digits than its factorization.

2171946981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38104355.

The product of its digits is 217728, while the sum is 48.

The square root of 2171946981 is about 46604.1519716860. The cubic root of 2171946981 is about 1295.0396734068.

The spelling of 2171946981 in words is "two billion, one hundred seventy-one million, nine hundred forty-six thousand, nine hundred eighty-one".