72581121 has 12 divisors (see below), whose sum is σ = 110357520. Its totient is φ = 45840600.

The previous prime is 72581063. The next prime is 72581141. The reversal of 72581121 is 12118527.

72581121 is a `hidden beast` number, since 72 + 581 + 12 + 1 = 666.

It is not a de Polignac number, because 72581121 - 2⁶ = 72581057 is a prime.

It is not an unprimeable number, because it can be changed into a prime (72581141) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 212055 + ... + 212396.

It is an arithmetic number, because the mean of its divisors is an integer number (9196460).

It is a Proth number, since it is equal to 2215 ⋅ 2¹⁵ + 1 and 2215 < 2¹⁵.

Almost surely, 2^72581121 is an apocalyptic number.

It is an amenable number.

72581121 is a deficient number, since it is larger than the sum of its proper divisors (37776399).

72581121 is a wasteful number, since it uses less digits than its factorization.

72581121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 424476 (or 424473 counting only the distinct ones).

The product of its digits is 1120, while the sum is 27.

The square root of 72581121 is about 8519.4554403436. The cubic root of 72581121 is about 417.1330079650.

Adding to 72581121 its reverse (12118527), we get a palindrome (84699648).

The spelling of 72581121 in words is "seventy-two million, five hundred eighty-one thousand, one hundred twenty-one".