71216640 has 240 divisors, whose sum is σ = 270022896. Its totient is φ = 17203200.

The previous prime is 71216627. The next prime is 71216681. The reversal of 71216640 is 4661217.

71216640 is a `hidden beast` number, since 7 + 1 + 2 + 16 + 640 = 666.

It is a tau number, because it is divible by the number of its divisors (240).

It is a congruent number.

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 23 ways as a sum of consecutive naturals, for example, 253300 + ... + 253580.

Almost surely, 2^71216640 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 71216640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (135011448).

71216640 is an abundant number, since it is smaller than the sum of its proper divisors (198806256).

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

71216640 is a wasteful number, since it uses less digits than its factorization.

71216640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 321 (or 302 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 71216640 is about 8438.9952008518. The cubic root of 71216640 is about 414.5025054136.

Adding to 71216640 its reverse (4661217), we get a palindrome (75877857).

The spelling of 71216640 in words is "seventy-one million, two hundred sixteen thousand, six hundred forty".