81359655 has 64 divisors (see below), whose sum is σ = 148549632. Its totient is φ = 37739520.

The previous prime is 81359647. The next prime is 81359659. The reversal of 81359655 is 55695318.

It is not a de Polignac number, because 81359655 - 2³ = 81359647 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81359659) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 259779 + ... + 260091.

It is an arithmetic number, because the mean of its divisors is an integer number (2321088).

Almost surely, 2^81359655 is an apocalyptic number.

81359655 is a deficient number, since it is larger than the sum of its proper divisors (67189977).

81359655 is a wasteful number, since it uses less digits than its factorization.

81359655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 408.

The product of its digits is 162000, while the sum is 42.

The square root of 81359655 is about 9019.9587027879. The cubic root of 81359655 is about 433.3143111308.

The spelling of 81359655 in words is "eighty-one million, three hundred fifty-nine thousand, six hundred fifty-five".