81658120155 has 32 divisors (see below), whose sum is σ = 132050378304. Its totient is φ = 43087589376.

The previous prime is 81658120151. The next prime is 81658120169. The reversal of 81658120155 is 55102185618.

It is not a de Polignac number, because 81658120155 - 2² = 81658120151 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81658120151) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 474307 + ... + 623123.

It is an arithmetic number, because the mean of its divisors is an integer number (4126574322).

Almost surely, 2^81658120155 is an apocalyptic number.

81658120155 is a deficient number, since it is larger than the sum of its proper divisors (50392258149).

81658120155 is a wasteful number, since it uses less digits than its factorization.

81658120155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 149215.

The product of its (nonzero) digits is 96000, while the sum is 42.

The spelling of 81658120155 in words is "eighty-one billion, six hundred fifty-eight million, one hundred twenty thousand, one hundred fifty-five".