86782165821 has 12 divisors (see below), whose sum is σ = 134994480348. Its totient is φ = 53404409664.

The previous prime is 86782165819. The next prime is 86782165871. The reversal of 86782165821 is 12856128768.

It can be written as a sum of positive squares in 2 ways, for example, as 5574264921 + 81207900900 = 74661^2 + 284970^2 .

It is not a de Polignac number, because 86782165821 - 2¹ = 86782165819 is a prime.

It is a super-2 number, since 2×86782165821² (a number of 23 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (86782165871) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 370863840 + ... + 370864073.

It is an arithmetic number, because the mean of its divisors is an integer number (11249540029).

Almost surely, 2^86782165821 is an apocalyptic number.

It is an amenable number.

86782165821 is a deficient number, since it is larger than the sum of its proper divisors (48212314527).

86782165821 is a wasteful number, since it uses less digits than its factorization.

86782165821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 741727932 (or 741727929 counting only the distinct ones).

The product of its digits is 2580480, while the sum is 54.

The spelling of 86782165821 in words is "eighty-six billion, seven hundred eighty-two million, one hundred sixty-five thousand, eight hundred twenty-one".