81320233311 has 8 divisors (see below), whose sum is σ = 120474419760. Its totient is φ = 54213488856.

The previous prime is 81320233303. The next prime is 81320233373. The reversal of 81320233311 is 11333202318.

81320233311 is a `hidden beast` number, since 8 + 1 + 320 + 2 + 3 + 331 + 1 = 666.

It is not a de Polignac number, because 81320233311 - 2³ = 81320233303 is a prime.

It is a super-2 number, since 2×81320233311² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 3011860493 = 81320233311 / (8 + 1 + 3 + 2 + 0 + 2 + 3 + 3 + 3 + 1 + 1).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81320232311) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1505930220 + ... + 1505930273.

It is an arithmetic number, because the mean of its divisors is an integer number (15059302470).

Almost surely, 2^81320233311 is an apocalyptic number.

81320233311 is a deficient number, since it is larger than the sum of its proper divisors (39154186449).

81320233311 is a wasteful number, since it uses less digits than its factorization.

81320233311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3011860502 (or 3011860496 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 27.

Adding to 81320233311 its reverse (11333202318), we get a palindrome (92653435629).

The spelling of 81320233311 in words is "eighty-one billion, three hundred twenty million, two hundred thirty-three thousand, three hundred eleven".