72565121 has 4 divisors (see below), whose sum is σ = 74335044. Its totient is φ = 70795200.

The previous prime is 72565111. The next prime is 72565169. The reversal of 72565121 is 12156527.

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 33640000 + 38925121 = 5800^2 + 6239^2 .

It is a cyclic number.

It is not a de Polignac number, because 72565121 - 2⁶ = 72565057 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72565111) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 884900 + ... + 884981.

It is an arithmetic number, because the mean of its divisors is an integer number (18583761).

Almost surely, 2^72565121 is an apocalyptic number.

It is an amenable number.

72565121 is a deficient number, since it is larger than the sum of its proper divisors (1769923).

72565121 is a wasteful number, since it uses less digits than its factorization.

72565121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1769922.

The product of its digits is 4200, while the sum is 29.

The square root of 72565121 is about 8518.5163614329. The cubic root of 72565121 is about 417.1023543619.

The spelling of 72565121 in words is "seventy-two million, five hundred sixty-five thousand, one hundred twenty-one".