72543649 has 4 divisors (see below), whose sum is σ = 72573120. Its totient is φ = 72514180.

The previous prime is 72543619. The next prime is 72543661. The reversal of 72543649 is 94634527.

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: 94634527 = 13 ⋅7279579.

It is a cyclic number.

It is not a de Polignac number, because 72543649 - 2⁵ = 72543617 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72543619) 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 3 ways as a sum of consecutive naturals, for example, 10669 + ... + 16090.

It is an arithmetic number, because the mean of its divisors is an integer number (18143280).

Almost surely, 2^72543649 is an apocalyptic number.

It is an amenable number.

72543649 is a deficient number, since it is larger than the sum of its proper divisors (29471).

72543649 is a wasteful number, since it uses less digits than its factorization.

72543649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29470.

The product of its digits is 181440, while the sum is 40.

The square root of 72543649 is about 8517.2559548249. The cubic root of 72543649 is about 417.0612101449.

The spelling of 72543649 in words is "seventy-two million, five hundred forty-three thousand, six hundred forty-nine".