71809011 has 40 divisors (see below), whose sum is σ = 112123440. Its totient is φ = 45759168.

The previous prime is 71808983. The next prime is 71809021. The reversal of 71809011 is 11090817.

It is not a de Polignac number, because 71809011 - 2⁷ = 71808883 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (71809021) 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 39 ways as a sum of consecutive naturals, for example, 184405 + ... + 184793.

It is an arithmetic number, because the mean of its divisors is an integer number (2803086).

Almost surely, 2^71809011 is an apocalyptic number.

71809011 is a deficient number, since it is larger than the sum of its proper divisors (40314429).

71809011 is a wasteful number, since it uses less digits than its factorization.

71809011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 497 (or 488 counting only the distinct ones).

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

The square root of 71809011 is about 8474.0197663211. The cubic root of 71809011 is about 415.6485933881.

Adding to 71809011 its reverse (11090817), we get a palindrome (82899828).

The spelling of 71809011 in words is "seventy-one million, eight hundred nine thousand, eleven".