81328877 has 12 divisors (see below), whose sum is σ = 94805820. Its totient is φ = 69564096.

The previous prime is 81328859. The next prime is 81328909. The reversal of 81328877 is 77882318.

It can be written as a sum of positive squares in 2 ways, for example, as 55785961 + 25542916 = 7469^2 + 5054^2 .

It is not a de Polignac number, because 81328877 - 2⁶ = 81328813 is a prime.

It is a super-2 number, since 2×81328877² = 13228772468162258, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81324877) 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 11 ways as a sum of consecutive naturals, for example, 26423 + ... + 29339.

It is an arithmetic number, because the mean of its divisors is an integer number (7900485).

Almost surely, 2^81328877 is an apocalyptic number.

It is an amenable number.

81328877 is a deficient number, since it is larger than the sum of its proper divisors (13476943).

81328877 is a wasteful number, since it uses less digits than its factorization.

81328877 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3500 (or 3493 counting only the distinct ones).

The product of its digits is 150528, while the sum is 44.

The square root of 81328877 is about 9018.2524360322. The cubic root of 81328877 is about 433.2596639393.

The spelling of 81328877 in words is "eighty-one million, three hundred twenty-eight thousand, eight hundred seventy-seven".