81071001 has 24 divisors (see below), whose sum is σ = 128440416. Its totient is φ = 48867840.

The previous prime is 81070963. The next prime is 81071009. The reversal of 81071001 is 10017018.

It is not a de Polignac number, because 81071001 - 2⁶ = 81070937 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81071009) 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 23 ways as a sum of consecutive naturals, for example, 16986 + ... + 21228.

It is an arithmetic number, because the mean of its divisors is an integer number (5351684).

Almost surely, 2^81071001 is an apocalyptic number.

It is an amenable number.

81071001 is a deficient number, since it is larger than the sum of its proper divisors (47369415).

81071001 is a wasteful number, since it uses less digits than its factorization.

81071001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4453 (or 4450 counting only the distinct ones).

The product of its (nonzero) digits is 56, while the sum is 18.

The square root of 81071001 is about 9003.9436359853. The cubic root of 81071001 is about 432.8012553591.

Adding to 81071001 its reverse (10017018), we get a palindrome (91088019).

The spelling of 81071001 in words is "eighty-one million, seventy-one thousand, one".