82686981 has 16 divisors (see below), whose sum is σ = 118979840. Its totient is φ = 50777280.

The previous prime is 82686949. The next prime is 82686991. The reversal of 82686981 is 18968628.

It is not a de Polignac number, because 82686981 - 2⁵ = 82686949 is a prime.

It is a super-2 number, since 2×82686981² = 13674273653788722, 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 82686981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (82686931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19140 + ... + 23058.

It is an arithmetic number, because the mean of its divisors is an integer number (7436240).

Almost surely, 2^82686981 is an apocalyptic number.

It is an amenable number.

82686981 is a deficient number, since it is larger than the sum of its proper divisors (36292859).

82686981 is a wasteful number, since it uses less digits than its factorization.

82686981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4476.

The product of its digits is 331776, while the sum is 48.

The square root of 82686981 is about 9093.2382020928. The cubic root of 82686981 is about 435.6580185234.

The spelling of 82686981 in words is "eighty-two million, six hundred eighty-six thousand, nine hundred eighty-one".