81581008358 has 16 divisors (see below), whose sum is σ = 128819400000. Its totient is φ = 38641451112.

The previous prime is 81581008337. The next prime is 81581008387. The reversal of 81581008358 is 85380018518.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 767033 + ... + 866891.

It is an arithmetic number, because the mean of its divisors is an integer number (8051212500).

Almost surely, 2^81581008358 is an apocalyptic number.

81581008358 is a deficient number, since it is larger than the sum of its proper divisors (47238391642).

81581008358 is a wasteful number, since it uses less digits than its factorization.

81581008358 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 121379.

The product of its (nonzero) digits is 307200, while the sum is 47.

The spelling of 81581008358 in words is "eighty-one billion, five hundred eighty-one million, eight thousand, three hundred fifty-eight".