71691840 has 336 divisors, whose sum is σ = 281488896. Its totient is φ = 16588800.

The previous prime is 71691791. The next prime is 71691877. The reversal of 71691840 is 4819617.

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 = 71691795 and 71691804.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 982044 + ... + 982116.

Almost surely, 2^71691840 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 71691840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (140744448).

71691840 is an abundant number, since it is smaller than the sum of its proper divisors (209797056).

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

71691840 is a wasteful number, since it uses less digits than its factorization.

71691840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138 (or 125 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 36.

The square root of 71691840 is about 8467.1034008095. The cubic root of 71691840 is about 415.4223985891.

It can be divided in two parts, 7169 and 1840, that added together give a palindrome (9009).

The spelling of 71691840 in words is "seventy-one million, six hundred ninety-one thousand, eight hundred forty".