72266881 has 4 divisors (see below), whose sum is σ = 76517892. Its totient is φ = 68015872.

The previous prime is 72266833. The next prime is 72266911. The reversal of 72266881 is 18866227.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 20657025 + 51609856 = 4545^2 + 7184^2 .

It is a cyclic number.

It is not a de Polignac number, because 72266881 - 2¹¹ = 72264833 is a prime.

It is a super-2 number, since 2×72266881² = 10445004178936322, which contains 22 as substring.

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 (72266801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2125480 + ... + 2125513.

It is an arithmetic number, because the mean of its divisors is an integer number (19129473).

Almost surely, 2^72266881 is an apocalyptic number.

72266881 is the 5377-th centered pentagonal number.

It is an amenable number.

72266881 is a deficient number, since it is larger than the sum of its proper divisors (4251011).

72266881 is a wasteful number, since it uses less digits than its factorization.

72266881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4251010.

The product of its digits is 64512, while the sum is 40.

The square root of 72266881 is about 8500.9929420039. The cubic root of 72266881 is about 416.5301445708.

The spelling of 72266881 in words is "seventy-two million, two hundred sixty-six thousand, eight hundred eighty-one".