72548561 has 4 divisors (see below), whose sum is σ = 72568500. Its totient is φ = 72528624.

The previous prime is 72548551. The next prime is 72548569. The reversal of 72548561 is 16584527.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16584527 = 89 ⋅186343.

It can be written as a sum of positive squares in 2 ways, for example, as 25200400 + 47348161 = 5020^2 + 6881^2 .

It is a cyclic number.

It is not a de Polignac number, because 72548561 - 2²⁶ = 5439697 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (72548569) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2786 + ... + 12363.

It is an arithmetic number, because the mean of its divisors is an integer number (18142125).

Almost surely, 2^72548561 is an apocalyptic number.

It is an amenable number.

72548561 is a deficient number, since it is larger than the sum of its proper divisors (19939).

72548561 is a wasteful number, since it uses less digits than its factorization.

72548561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19938.

The product of its digits is 67200, while the sum is 38.

The square root of 72548561 is about 8517.5443057257. The cubic root of 72548561 is about 417.0706231372.

The spelling of 72548561 in words is "seventy-two million, five hundred forty-eight thousand, five hundred sixty-one".