71216660 has 12 divisors (see below), whose sum is σ = 149555028. Its totient is φ = 28486656.

The previous prime is 71216627. The next prime is 71216681. The reversal of 71216660 is 6661217.

It can be written as a sum of positive squares in 2 ways, for example, as 56731024 + 14485636 = 7532^2 + 3806^2 .

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 3 ways as a sum of consecutive naturals, for example, 1780397 + ... + 1780436.

It is an arithmetic number, because the mean of its divisors is an integer number (12462919).

Almost surely, 2^71216660 is an apocalyptic number.

It is an amenable number.

71216660 is an abundant number, since it is smaller than the sum of its proper divisors (78338368).

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

71216660 is a wasteful number, since it uses less digits than its factorization.

71216660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3560842 (or 3560840 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 29.

The square root of 71216660 is about 8438.9963858269. The cubic root of 71216660 is about 414.5025442156.

Adding to 71216660 its reverse (6661217), we get a palindrome (77877877).

The spelling of 71216660 in words is "seventy-one million, two hundred sixteen thousand, six hundred sixty".