81192427478 has 16 divisors (see below), whose sum is σ = 121921800000. Its totient is φ = 40551855552.

The previous prime is 81192427457. The next prime is 81192427487. The reversal of 81192427478 is 87472429118.

It is a Smith number, since the sum of its digits (53) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8106938 + ... + 8116946.

It is an arithmetic number, because the mean of its divisors is an integer number (7620112500).

Almost surely, 2^81192427478 is an apocalyptic number.

81192427478 is a deficient number, since it is larger than the sum of its proper divisors (40729372522).

81192427478 is a wasteful number, since it uses less digits than its factorization.

81192427478 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14039.

The product of its digits is 1806336, while the sum is 53.

The spelling of 81192427478 in words is "eighty-one billion, one hundred ninety-two million, four hundred twenty-seven thousand, four hundred seventy-eight".