71817840 has 100 divisors (see below), whose sum is σ = 249456504. Its totient is φ = 19149696.

The previous prime is 71817839. The next prime is 71817871. The reversal of 71817840 is 4871817.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 71817795 and 71817804.

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 19 ways as a sum of consecutive naturals, for example, 939 + ... + 12021.

Almost surely, 2^71817840 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 71817840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (124728252).

71817840 is an abundant number, since it is smaller than the sum of its proper divisors (177638664).

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

71817840 is a wasteful number, since it uses less digits than its factorization.

71817840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11108 (or 11093 counting only the distinct ones).

The product of its (nonzero) digits is 12544, while the sum is 36.

The square root of 71817840 is about 8474.5406955185. The cubic root of 71817840 is about 415.6656275132.

The spelling of 71817840 in words is "seventy-one million, eight hundred seventeen thousand, eight hundred forty".