81992055 has 16 divisors (see below), whose sum is σ = 135419904. Its totient is φ = 42318240.

The previous prime is 81992047. The next prime is 81992059. The reversal of 81992055 is 55029918.

It is not a de Polignac number, because 81992055 - 2³ = 81992047 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81992059) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 87699 + ... + 88628.

It is an arithmetic number, because the mean of its divisors is an integer number (8463744).

Almost surely, 2^81992055 is an apocalyptic number.

81992055 is a deficient number, since it is larger than the sum of its proper divisors (53427849).

81992055 is a wasteful number, since it uses less digits than its factorization.

81992055 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 176366.

The product of its (nonzero) digits is 32400, while the sum is 39.

The square root of 81992055 is about 9054.9464382734. The cubic root of 81992055 is about 434.4341168613.

The spelling of 81992055 in words is "eighty-one million, nine hundred ninety-two thousand, fifty-five".