81387755580148 has 24 divisors (see below), whose sum is σ = 143052770474600. Its totient is φ = 40515888251520.

The previous prime is 81387755580073. The next prime is 81387755580163. The reversal of 81387755580148 is 84108555778318.

It can be written as a sum of positive squares in 4 ways, for example, as 47688941095524 + 33698814484624 = 6905718^2 + 5805068^2 .

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, 43177611 + ... + 45023122.

Almost surely, 2^{81387755580148} is an apocalyptic number.

It is an amenable number.

81387755580148 is a deficient number, since it is larger than the sum of its proper divisors (61665014894452).

81387755580148 is a wasteful number, since it uses less digits than its factorization.

81387755580148 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88201747 (or 88201745 counting only the distinct ones).

The product of its (nonzero) digits is 301056000, while the sum is 70.

The spelling of 81387755580148 in words is "eighty-one trillion, three hundred eighty-seven billion, seven hundred fifty-five million, five hundred eighty thousand, one hundred forty-eight".