72521530 has 32 divisors (see below), whose sum is σ = 138163968. Its totient is φ = 27350400.

The previous prime is 72521503. The next prime is 72521531. The reversal of 72521530 is 3512527.

It is a junction number, because it is equal to n+sod(n) for n = 72521495 and 72521504.

It is not an unprimeable number, because it can be changed into a prime (72521531) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 14110 + ... + 18550.

It is an arithmetic number, because the mean of its divisors is an integer number (4317624).

Almost surely, 2^72521530 is an apocalyptic number.

72521530 is a deficient number, since it is larger than the sum of its proper divisors (65642438).

72521530 is a wasteful number, since it uses less digits than its factorization.

72521530 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4542.

The product of its (nonzero) digits is 2100, while the sum is 25.

The square root of 72521530 is about 8515.9573742475. The cubic root of 72521530 is about 417.0188176691.

The spelling of 72521530 in words is "seventy-two million, five hundred twenty-one thousand, five hundred thirty".