81667471020 has 24 divisors (see below), whose sum is σ = 228668919024. Its totient is φ = 21777992256.

The previous prime is 81667471009. The next prime is 81667471033. The reversal of 81667471020 is 2017476618.

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 7 ways as a sum of consecutive naturals, for example, 680562199 + ... + 680562318.

It is an arithmetic number, because the mean of its divisors is an integer number (9527871626).

Almost surely, 2^81667471020 is an apocalyptic number.

It is an amenable number.

81667471020 is an abundant number, since it is smaller than the sum of its proper divisors (147001448004).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81667471020 is a wasteful number, since it uses less digits than its factorization.

81667471020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1361124529 (or 1361124527 counting only the distinct ones).

The product of its (nonzero) digits is 112896, while the sum is 42.

The spelling of 81667471020 in words is "eighty-one billion, six hundred sixty-seven million, four hundred seventy-one thousand, twenty".