72125609 has 4 divisors (see below), whose sum is σ = 72143316. Its totient is φ = 72107904.

The previous prime is 72125593. The next prime is 72125621. The reversal of 72125609 is 90652127.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 26265625 + 45859984 = 5125^2 + 6772^2 .

It is a cyclic number.

It is not a de Polignac number, because 72125609 - 2⁴ = 72125593 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72125699) 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, 677 + ... + 12029.

It is an arithmetic number, because the mean of its divisors is an integer number (18035829).

Almost surely, 2^72125609 is an apocalyptic number.

It is an amenable number.

72125609 is a deficient number, since it is larger than the sum of its proper divisors (17707).

72125609 is a wasteful number, since it uses less digits than its factorization.

72125609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17706.

The product of its (nonzero) digits is 7560, while the sum is 32.

The square root of 72125609 is about 8492.6797302147. The cubic root of 72125609 is about 416.2585474412.

It can be divided in two parts, 7212 and 5609, that added together give a palindrome (12821).

The spelling of 72125609 in words is "seventy-two million, one hundred twenty-five thousand, six hundred nine".