81027801 has 12 divisors (see below), whose sum is σ = 117310128. Its totient is φ = 53893944.

The previous prime is 81027787. The next prime is 81027809. The reversal of 81027801 is 10872018.

It is not a de Polignac number, because 81027801 - 2⁷ = 81027673 is a prime.

It is a Smith number, since the sum of its digits (27) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (81027809) 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 11 ways as a sum of consecutive naturals, for example, 6175 + ... + 14148.

It is an arithmetic number, because the mean of its divisors is an integer number (9775844).

Almost surely, 2^81027801 is an apocalyptic number.

It is an amenable number.

81027801 is a deficient number, since it is larger than the sum of its proper divisors (36282327).

81027801 is a wasteful number, since it uses less digits than its factorization.

81027801 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20772 (or 20769 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 27.

The square root of 81027801 is about 9001.5443674961. The cubic root of 81027801 is about 432.7243666402.

Adding to 81027801 its reverse (10872018), we get a palindrome (91899819).

The spelling of 81027801 in words is "eighty-one million, twenty-seven thousand, eight hundred one".