72305640 has 288 divisors, whose sum is σ = 278834400. Its totient is φ = 16070400.

The previous prime is 72305633. The next prime is 72305657. The reversal of 72305640 is 4650327.

It is a happy number.

72305640 is a `hidden beast` number, since 72 + 30 + 564 + 0 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 2332425 + ... + 2332455.

It is an arithmetic number, because the mean of its divisors is an integer number (968175).

Almost surely, 2^72305640 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 72305640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (139417200).

72305640 is an abundant number, since it is smaller than the sum of its proper divisors (206528760).

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

72305640 is a wasteful number, since it uses less digits than its factorization.

72305640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109 (or 71 counting only the distinct ones).

The product of its (nonzero) digits is 5040, while the sum is 27.

The square root of 72305640 is about 8503.2723112929. The cubic root of 72305640 is about 416.6045973320.

Adding to 72305640 its reverse (4650327), we get a palindrome (76955967).

The spelling of 72305640 in words is "seventy-two million, three hundred five thousand, six hundred forty".