81748432978 has 16 divisors (see below), whose sum is σ = 126859426560. Its totient is φ = 39462144400.

The previous prime is 81748432963. The next prime is 81748433009. The reversal of 81748432978 is 87923484718.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1059573 + ... + 1134103.

It is an arithmetic number, because the mean of its divisors is an integer number (7928714160).

Almost surely, 2^81748432978 is an apocalyptic number.

81748432978 is a deficient number, since it is larger than the sum of its proper divisors (45110993582).

81748432978 is a wasteful number, since it uses less digits than its factorization.

81748432978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 93473.

The product of its digits is 21676032, while the sum is 61.

The spelling of 81748432978 in words is "eighty-one billion, seven hundred forty-eight million, four hundred thirty-two thousand, nine hundred seventy-eight".