72505217 has 4 divisors (see below), whose sum is σ = 72985536. Its totient is φ = 72024900.

The previous prime is 72505183. The next prime is 72505229. The reversal of 72505217 is 71250527.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 72505217 - 2²⁰ = 71456641 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 72505217.

It is not an unprimeable number, because it can be changed into a prime (72505117) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 239933 + ... + 240234.

It is an arithmetic number, because the mean of its divisors is an integer number (18246384).

Almost surely, 2^72505217 is an apocalyptic number.

It is an amenable number.

72505217 is a deficient number, since it is larger than the sum of its proper divisors (480319).

72505217 is a wasteful number, since it uses less digits than its factorization.

72505217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 480318.

The product of its (nonzero) digits is 4900, while the sum is 29.

The square root of 72505217 is about 8514.9995302407. Note that the first 3 decimals coincide. The cubic root of 72505217 is about 416.9875472399.

The spelling of 72505217 in words is "seventy-two million, five hundred five thousand, two hundred seventeen".