81085083188 has 6 divisors (see below), whose sum is σ = 141898895586. Its totient is φ = 40542541592.

The previous prime is 81085083173. The next prime is 81085083227. The reversal of 81085083188 is 88138058018.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 80986914724 + 98168464 = 284582^2 + 9908^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10135635395 + ... + 10135635402.

It is an arithmetic number, because the mean of its divisors is an integer number (23649815931).

Almost surely, 2^81085083188 is an apocalyptic number.

It is an amenable number.

81085083188 is a deficient number, since it is larger than the sum of its proper divisors (60813812398).

81085083188 is a wasteful number, since it uses less digits than its factorization.

81085083188 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20271270801 (or 20271270799 counting only the distinct ones).

The product of its (nonzero) digits is 491520, while the sum is 50.

The spelling of 81085083188 in words is "eighty-one billion, eighty-five million, eighty-three thousand, one hundred eighty-eight".