72116640 has 144 divisors (see below), whose sum is σ = 250437096. Its totient is φ = 18892800.

The previous prime is 72116621. The next prime is 72116657. The reversal of 72116640 is 4661127.

72116640 is a `hidden beast` number, since 7 + 2 + 1 + 16 + 640 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 29030544 + 43086096 = 5388^2 + 6564^2 .

It is a tau number, because it is divible by the number of its divisors (144).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 87430 + ... + 88250.

Almost surely, 2^72116640 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 72116640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (125218548).

72116640 is an abundant number, since it is smaller than the sum of its proper divisors (178320456).

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

72116640 is a wasteful number, since it uses less digits than its factorization.

72116640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 903 (or 892 counting only the distinct ones).

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

The square root of 72116640 is about 8492.1516708076. The cubic root of 72116640 is about 416.2412924618.

Adding to 72116640 its reverse (4661127), we get a palindrome (76777767).

The spelling of 72116640 in words is "seventy-two million, one hundred sixteen thousand, six hundred forty".