82170981 has 12 divisors (see below), whose sum is σ = 120194880. Its totient is φ = 54086760.

The previous prime is 82170961. The next prime is 82170983. The reversal of 82170981 is 18907128.

It is a de Polignac number, because none of the positive numbers 2^k-82170981 is a prime.

It is a super-2 number, since 2×82170981² = 13504140237004722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (82170983) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 57075 + ... + 58496.

It is an arithmetic number, because the mean of its divisors is an integer number (10016240).

Almost surely, 2^82170981 is an apocalyptic number.

It is an amenable number.

82170981 is a deficient number, since it is larger than the sum of its proper divisors (38023899).

82170981 is a wasteful number, since it uses less digits than its factorization.

82170981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 115656 (or 115653 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 36.

The square root of 82170981 is about 9064.8210682837. The cubic root of 82170981 is about 434.7498998331.

The spelling of 82170981 in words is "eighty-two million, one hundred seventy thousand, nine hundred eighty-one".