81824017820 has 96 divisors (see below), whose sum is σ = 176197012992. Its totient is φ = 31910600448.

The previous prime is 81824017811. The next prime is 81824017837. The reversal of 81824017820 is 2871042818.

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 63774899 + ... + 63776181.

It is an arithmetic number, because the mean of its divisors is an integer number (1835385552).

Almost surely, 2^81824017820 is an apocalyptic number.

It is an amenable number.

81824017820 is an abundant number, since it is smaller than the sum of its proper divisors (94372995172).

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

81824017820 is a wasteful number, since it uses less digits than its factorization.

81824017820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1851 (or 1849 counting only the distinct ones).

The product of its (nonzero) digits is 57344, while the sum is 41.

The spelling of 81824017820 in words is "eighty-one billion, eight hundred twenty-four million, seventeen thousand, eight hundred twenty".