71809871 has 16 divisors (see below), whose sum is σ = 85375488. Its totient is φ = 59119200.

The previous prime is 71809867. The next prime is 71809879. The reversal of 71809871 is 17890817.

It is not a de Polignac number, because 71809871 - 2² = 71809867 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71809879) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16406 + ... + 20316.

It is an arithmetic number, because the mean of its divisors is an integer number (5335968).

Almost surely, 2^71809871 is an apocalyptic number.

71809871 is a deficient number, since it is larger than the sum of its proper divisors (13565617).

71809871 is a wasteful number, since it uses less digits than its factorization.

71809871 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4022.

The product of its (nonzero) digits is 28224, while the sum is 41.

The square root of 71809871 is about 8474.0705095013. The cubic root of 71809871 is about 415.6502526801.

The spelling of 71809871 in words is "seventy-one million, eight hundred nine thousand, eight hundred seventy-one".