71781668 has 48 divisors (see below), whose sum is σ = 148108800. Its totient is φ = 30425472.

The previous prime is 71781659. The next prime is 71781683. The reversal of 71781668 is 86618717.

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 15 ways as a sum of consecutive naturals, for example, 154805 + ... + 155267.

It is an arithmetic number, because the mean of its divisors is an integer number (3085600).

Almost surely, 2^71781668 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 71781668, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (74054400).

71781668 is an abundant number, since it is smaller than the sum of its proper divisors (76327132).

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

71781668 is a wasteful number, since it uses less digits than its factorization.

71781668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 601 (or 585 counting only the distinct ones).

The product of its digits is 112896, while the sum is 44.

The square root of 71781668 is about 8472.4062697678. The cubic root of 71781668 is about 415.5958306399.

The spelling of 71781668 in words is "seventy-one million, seven hundred eighty-one thousand, six hundred sixty-eight".