81266359 has 4 divisors (see below), whose sum is σ = 81500904. Its totient is φ = 81031816.

The previous prime is 81266357. The next prime is 81266369. The reversal of 81266359 is 95366218.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 95366218 = 2 ⋅47683109.

It is a cyclic number.

It is not a de Polignac number, because 81266359 - 2¹ = 81266357 is a prime.

It is a super-2 number, since 2×81266359² = 13208442210233762, which contains 22 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81266351) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 116752 + ... + 117445.

It is an arithmetic number, because the mean of its divisors is an integer number (20375226).

Almost surely, 2^81266359 is an apocalyptic number.

81266359 is a deficient number, since it is larger than the sum of its proper divisors (234545).

81266359 is a wasteful number, since it uses less digits than its factorization.

81266359 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 234544.

The product of its digits is 77760, while the sum is 40.

The square root of 81266359 is about 9014.7855770395. The cubic root of 81266359 is about 433.1486190388.

The spelling of 81266359 in words is "eighty-one million, two hundred sixty-six thousand, three hundred fifty-nine".