81640415055 has 16 divisors (see below), whose sum is σ = 130635752544. Its totient is φ = 43537858560.

The previous prime is 81640415053. The next prime is 81640415099. The reversal of 81640415055 is 55051404618.

It is not a de Polignac number, because 81640415055 - 2¹ = 81640415053 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81640415053) 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 15 ways as a sum of consecutive naturals, for example, 43506 + ... + 406415.

It is an arithmetic number, because the mean of its divisors is an integer number (8164734534).

Almost surely, 2^81640415055 is an apocalyptic number.

81640415055 is a deficient number, since it is larger than the sum of its proper divisors (48995337489).

81640415055 is a wasteful number, since it uses less digits than its factorization.

81640415055 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 462026.

The product of its (nonzero) digits is 96000, while the sum is 39.

The spelling of 81640415055 in words is "eighty-one billion, six hundred forty million, four hundred fifteen thousand, fifty-five".