81686607146 has 32 divisors (see below), whose sum is σ = 132550629120. Its totient is φ = 37607904256.

The previous prime is 81686607139. The next prime is 81686607161. The reversal of 81686607146 is 64170668618.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4687826 + ... + 4705218.

It is an arithmetic number, because the mean of its divisors is an integer number (4142207160).

Almost surely, 2^81686607146 is an apocalyptic number.

81686607146 is a deficient number, since it is larger than the sum of its proper divisors (50864021974).

81686607146 is a wasteful number, since it uses less digits than its factorization.

81686607146 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20398.

The product of its (nonzero) digits is 2322432, while the sum is 53.

The spelling of 81686607146 in words is "eighty-one billion, six hundred eighty-six million, six hundred seven thousand, one hundred forty-six".