71440809 has 16 divisors (see below), whose sum is σ = 104583360. Its totient is φ = 43018560.

The previous prime is 71440807. The next prime is 71440813. The reversal of 71440809 is 90804417.

It is not a de Polignac number, because 71440809 - 2¹ = 71440807 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 71440809.

It is not an unprimeable number, because it can be changed into a prime (71440807) 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, 1714 + ... + 12075.

It is an arithmetic number, because the mean of its divisors is an integer number (6536460).

Almost surely, 2^71440809 is an apocalyptic number.

It is an amenable number.

71440809 is a deficient number, since it is larger than the sum of its proper divisors (33142551).

71440809 is a wasteful number, since it uses less digits than its factorization.

71440809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13960.

The product of its (nonzero) digits is 8064, while the sum is 33.

The square root of 71440809 is about 8452.2665007677. The cubic root of 71440809 is about 414.9369604735.

The spelling of 71440809 in words is "seventy-one million, four hundred forty thousand, eight hundred nine".