81016881 has 24 divisors (see below), whose sum is σ = 120210720. Its totient is φ = 48491520.

The previous prime is 81016829. The next prime is 81016891. The reversal of 81016881 is 18861018.

It is not a de Polignac number, because 81016881 - 2⁷ = 81016753 is a prime.

It is a super-2 number, since 2×81016881² = 13127470013936322, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (81016891) 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 23 ways as a sum of consecutive naturals, for example, 28785 + ... + 31473.

It is an arithmetic number, because the mean of its divisors is an integer number (5008780).

Almost surely, 2^81016881 is an apocalyptic number.

It is an amenable number.

81016881 is a deficient number, since it is larger than the sum of its proper divisors (39193839).

81016881 is a wasteful number, since it uses less digits than its factorization.

81016881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2797 (or 2786 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 33.

The square root of 81016881 is about 9000.9377844756. The cubic root of 81016881 is about 432.7049265538.

Adding to 81016881 its reverse (18861018), we get a palindrome (99877899).

The spelling of 81016881 in words is "eighty-one million, sixteen thousand, eight hundred eighty-one".