81866146367 has 16 divisors (see below), whose sum is σ = 85011696000. Its totient is φ = 78785257824.

The previous prime is 81866146333. The next prime is 81866146403. The reversal of 81866146367 is 76364166818.

It is a cyclic number.

It is not a de Polignac number, because 81866146367 - 2¹⁰ = 81866145343 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81866136367) 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 15 ways as a sum of consecutive naturals, for example, 790184 + ... + 887762.

It is an arithmetic number, because the mean of its divisors is an integer number (5313231000).

Almost surely, 2^81866146367 is an apocalyptic number.

81866146367 is a deficient number, since it is larger than the sum of its proper divisors (3145549633).

81866146367 is a wasteful number, since it uses less digits than its factorization.

81866146367 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 97910.

The product of its digits is 6967296, while the sum is 56.

The spelling of 81866146367 in words is "eighty-one billion, eight hundred sixty-six million, one hundred forty-six thousand, three hundred sixty-seven".