71809144 has 48 divisors (see below), whose sum is σ = 152832960. Its totient is φ = 31574400.

The previous prime is 71809123. The next prime is 71809169. The reversal of 71809144 is 44190817.

It is a congruent number.

It is an unprimeable number.

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, 28812 + ... + 31204.

It is an arithmetic number, because the mean of its divisors is an integer number (3184020).

Almost surely, 2^71809144 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 71809144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (76416480).

71809144 is an abundant number, since it is smaller than the sum of its proper divisors (81023816).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

71809144 is a wasteful number, since it uses less digits than its factorization.

71809144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2452 (or 2437 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 34.

The square root of 71809144 is about 8474.0276138328. The cubic root of 71809144 is about 415.6488500004.

The spelling of 71809144 in words is "seventy-one million, eight hundred nine thousand, one hundred forty-four".