72818505 has 12 divisors (see below), whose sum is σ = 126218820. Its totient is φ = 38836512.

The previous prime is 72818491. The next prime is 72818509. The reversal of 72818505 is 50581827.

72818505 is a `hidden beast` number, since 72 + 81 + 8 + 505 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 43917129 + 28901376 = 6627^2 + 5376^2 .

It is not a de Polignac number, because 72818505 - 2⁶ = 72818441 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 72818505.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72818509) 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, 809050 + ... + 809139.

It is an arithmetic number, because the mean of its divisors is an integer number (10518235).

Almost surely, 2^72818505 is an apocalyptic number.

It is an amenable number.

72818505 is a deficient number, since it is larger than the sum of its proper divisors (53400315).

72818505 is a wasteful number, since it uses less digits than its factorization.

72818505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1618200 (or 1618197 counting only the distinct ones).

The product of its (nonzero) digits is 22400, while the sum is 36.

The square root of 72818505 is about 8533.3759439040. The cubic root of 72818505 is about 417.5872718464.

The spelling of 72818505 in words is "seventy-two million, eight hundred eighteen thousand, five hundred five".