72521280 has 252 divisors, whose sum is σ = 271919700. Its totient is φ = 17731584.

The previous prime is 72521261. The next prime is 72521287. The reversal of 72521280 is 8212527.

It can be written as a sum of positive squares in 6 ways, for example, as 28643904 + 43877376 = 5352^2 + 6624^2 .

It is not an unprimeable number, because it can be changed into a prime (72521287) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 486646 + ... + 486794.

Almost surely, 2^72521280 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 72521280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (135959850).

72521280 is an abundant number, since it is smaller than the sum of its proper divisors (199398420).

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

72521280 is a wasteful number, since it uses less digits than its factorization.

72521280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 198 (or 172 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 27.

The square root of 72521280 is about 8515.9426959087. The cubic root of 72521280 is about 417.0183384789.

The spelling of 72521280 in words is "seventy-two million, five hundred twenty-one thousand, two hundred eighty".