8166668701565 has 12 divisors (see below), whose sum is σ = 10771903511292. Its totient is φ = 5939395418880.

The previous prime is 8166668701561. The next prime is 8166668701573. The reversal of 8166668701565 is 5651078666618.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 6239294588164 + 1927374113401 = 2497858^2 + 1388299^2 .

It is not a de Polignac number, because 8166668701565 - 2² = 8166668701561 is a prime.

It is a super-2 number, since 2×8166668701565² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8166668701561) 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, 6749312372 + ... + 6749313581.

It is an arithmetic number, because the mean of its divisors is an integer number (897658625941).

Almost surely, 2^{8166668701565} is an apocalyptic number.

It is an amenable number.

8166668701565 is a deficient number, since it is larger than the sum of its proper divisors (2605234809727).

8166668701565 is a wasteful number, since it uses less digits than its factorization.

8166668701565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13498625980 (or 13498625969 counting only the distinct ones).

The product of its (nonzero) digits is 87091200, while the sum is 65.

The spelling of 8166668701565 in words is "eight trillion, one hundred sixty-six billion, six hundred sixty-eight million, seven hundred one thousand, five hundred sixty-five".