81188455 has 16 divisors (see below), whose sum is σ = 98620704. Its totient is φ = 64160640.

The previous prime is 81188453. The next prime is 81188467. The reversal of 81188455 is 55488118.

It is not a de Polignac number, because 81188455 - 2¹ = 81188453 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81188453) 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, 255957 + ... + 256273.

It is an arithmetic number, because the mean of its divisors is an integer number (6163794).

Almost surely, 2^81188455 is an apocalyptic number.

81188455 is a deficient number, since it is larger than the sum of its proper divisors (17432249).

81188455 is a wasteful number, since it uses less digits than its factorization.

81188455 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 786.

The product of its digits is 51200, while the sum is 40.

The square root of 81188455 is about 9010.4636395693. The cubic root of 81188455 is about 433.0101656911.

The spelling of 81188455 in words is "eighty-one million, one hundred eighty-eight thousand, four hundred fifty-five".