81594340655 has 32 divisors (see below), whose sum is σ = 102033899520. Its totient is φ = 62570568960.

The previous prime is 81594340631. The next prime is 81594340657. The reversal of 81594340655 is 55604349518.

It is not a de Polignac number, because 81594340655 - 2⁶ = 81594340591 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81594340657) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 9841922 + ... + 9850208.

It is an arithmetic number, because the mean of its divisors is an integer number (3188559360).

Almost surely, 2^81594340655 is an apocalyptic number.

81594340655 is a deficient number, since it is larger than the sum of its proper divisors (20439558865).

81594340655 is a wasteful number, since it uses less digits than its factorization.

81594340655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8919.

The product of its (nonzero) digits is 2592000, while the sum is 50.

The spelling of 81594340655 in words is "eighty-one billion, five hundred ninety-four million, three hundred forty thousand, six hundred fifty-five".