81428055 has 16 divisors (see below), whose sum is σ = 130399584. Its totient is φ = 43390080.

The previous prime is 81428029. The next prime is 81428057. The reversal of 81428055 is 55082418.

It is not a de Polignac number, because 81428055 - 2⁵ = 81428023 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81428057) 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 15 ways as a sum of consecutive naturals, for example, 26457 + ... + 29373.

It is an arithmetic number, because the mean of its divisors is an integer number (8149974).

Almost surely, 2^81428055 is an apocalyptic number.

81428055 is a deficient number, since it is larger than the sum of its proper divisors (48971529).

81428055 is a wasteful number, since it uses less digits than its factorization.

81428055 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4786.

The product of its (nonzero) digits is 12800, while the sum is 33.

The square root of 81428055 is about 9023.7494978529. The cubic root of 81428055 is about 433.4357078964.

The spelling of 81428055 in words is "eighty-one million, four hundred twenty-eight thousand, fifty-five".