71808940 has 24 divisors (see below), whose sum is σ = 172341792. Its totient is φ = 24620160.

The previous prime is 71808937. The next prime is 71808941. The reversal of 71808940 is 4980817.

It is a self number, because there is not a number n which added to its sum of digits gives 71808940.

It is not an unprimeable number, because it can be changed into a prime (71808941) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 256321 + ... + 256600.

It is an arithmetic number, because the mean of its divisors is an integer number (7180908).

Almost surely, 2^71808940 is an apocalyptic number.

71808940 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

71808940 is an abundant number, since it is smaller than the sum of its proper divisors (100532852).

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

71808940 is a wasteful number, since it uses less digits than its factorization.

71808940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 512937 (or 512935 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 37.

The square root of 71808940 is about 8474.0155770449. The cubic root of 71808940 is about 415.6484563994.

The spelling of 71808940 in words is "seventy-one million, eight hundred eight thousand, nine hundred forty".