81355344 has 40 divisors (see below), whose sum is σ = 240192960. Its totient is φ = 23244288.

The previous prime is 81355331. The next prime is 81355349. The reversal of 81355344 is 44355318.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81355349) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 120729 + ... + 121400.

It is an arithmetic number, because the mean of its divisors is an integer number (6004824).

Almost surely, 2^81355344 is an apocalyptic number.

81355344 is a gapful number since it is divisible by the number (84) formed by its first and last digit.

It is an amenable number.

81355344 is an abundant number, since it is smaller than the sum of its proper divisors (158837616).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81355344 is a wasteful number, since it uses less digits than its factorization.

81355344 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 242147 (or 242141 counting only the distinct ones).

The product of its digits is 28800, while the sum is 33.

The square root of 81355344 is about 9019.7197295703. The cubic root of 81355344 is about 433.3066576610.

The spelling of 81355344 in words is "eighty-one million, three hundred fifty-five thousand, three hundred forty-four".