81930378456 has 48 divisors (see below), whose sum is σ = 229546324800. Its totient is φ = 26368396992.

The previous prime is 81930378449. The next prime is 81930378457. The reversal of 81930378456 is 65487303918.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81930378457) 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 11 ways as a sum of consecutive naturals, for example, 19617256 + ... + 19621431.

It is an arithmetic number, because the mean of its divisors is an integer number (4782215100).

Almost surely, 2^81930378456 is an apocalyptic number.

It is an amenable number.

81930378456 is an abundant number, since it is smaller than the sum of its proper divisors (147615946344).

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

81930378456 is a wasteful number, since it uses less digits than its factorization.

81930378456 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39238728 (or 39238721 counting only the distinct ones).

The product of its (nonzero) digits is 4354560, while the sum is 54.

The spelling of 81930378456 in words is "eighty-one billion, nine hundred thirty million, three hundred seventy-eight thousand, four hundred fifty-six".