72810561 has 16 divisors (see below), whose sum is σ = 103147200. Its totient is φ = 45597888.

The previous prime is 72810559. The next prime is 72810581. The reversal of 72810561 is 16501827.

It is not a de Polignac number, because 72810561 - 2¹ = 72810559 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (72810581) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8091 + ... + 14528.

It is an arithmetic number, because the mean of its divisors is an integer number (6446700).

Almost surely, 2^72810561 is an apocalyptic number.

It is an amenable number.

72810561 is a deficient number, since it is larger than the sum of its proper divisors (30336639).

72810561 is a wasteful number, since it uses less digits than its factorization.

72810561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22688.

The product of its (nonzero) digits is 3360, while the sum is 30.

The square root of 72810561 is about 8532.9104647828. The cubic root of 72810561 is about 417.5720859907.

The spelling of 72810561 in words is "seventy-two million, eight hundred ten thousand, five hundred sixty-one".