72561 has 12 divisors (see below), whose sum is σ = 103632. Its totient is φ = 45144.

The previous prime is 72559. The next prime is 72577. The reversal of 72561 is 16527.

It is not a de Polignac number, because 72561 - 2¹ = 72559 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 72561.

It is not an unprimeable number, because it can be changed into a prime (72551) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1050 + ... + 1116.

It is an arithmetic number, because the mean of its divisors is an integer number (8636).

2⁷²⁵⁶¹ is an apocalyptic number.

It is an amenable number.

72561 is a deficient number, since it is larger than the sum of its proper divisors (31071).

72561 is a wasteful number, since it uses less digits than its factorization.

72561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 108 (or 89 counting only the distinct ones).

The product of its digits is 420, while the sum is 21.

The square root of 72561 is about 269.3714906964. The cubic root of 72561 is about 41.7094458414.

The spelling of 72561 in words is "seventy-two thousand, five hundred sixty-one".