72756609 has 4 divisors (see below), whose sum is σ = 97008816. Its totient is φ = 48504404.

The previous prime is 72756599. The next prime is 72756623. The reversal of 72756609 is 90665727.

It is a happy number.

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, and also an emirpimes, since its reverse is a distinct semiprime: 90665727 = 3 ⋅30221909.

It is a cyclic number.

It is not a de Polignac number, because 72756609 - 2¹² = 72752513 is a prime.

It is not an unprimeable number, because it can be changed into a prime (72756109) 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, 12126099 + ... + 12126104.

It is an arithmetic number, because the mean of its divisors is an integer number (24252204).

Almost surely, 2^72756609 is an apocalyptic number.

It is an amenable number.

72756609 is a deficient number, since it is larger than the sum of its proper divisors (24252207).

72756609 is a wasteful number, since it uses less digits than its factorization.

72756609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24252206.

The product of its (nonzero) digits is 158760, while the sum is 42.

The square root of 72756609 is about 8529.7484722587. The cubic root of 72756609 is about 417.4689213960.

The spelling of 72756609 in words is "seventy-two million, seven hundred fifty-six thousand, six hundred nine".