81009711 has 12 divisors (see below), whose sum is σ = 123172920. Its totient is φ = 51163920.

The previous prime is 81009707. The next prime is 81009737. The reversal of 81009711 is 11790018.

It is not a de Polignac number, because 81009711 - 2² = 81009707 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81009751) 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, 236700 + ... + 237041.

It is an arithmetic number, because the mean of its divisors is an integer number (10264410).

Almost surely, 2^81009711 is an apocalyptic number.

81009711 is a deficient number, since it is larger than the sum of its proper divisors (42163209).

81009711 is a wasteful number, since it uses less digits than its factorization.

81009711 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 473766 (or 473763 counting only the distinct ones).

The product of its (nonzero) digits is 504, while the sum is 27.

The square root of 81009711 is about 9000.5394838310. The cubic root of 81009711 is about 432.6921613711.

Adding to 81009711 its reverse (11790018), we get a palindrome (92799729).

The spelling of 81009711 in words is "eighty-one million, nine thousand, seven hundred eleven".