72504121 has 4 divisors (see below), whose sum is σ = 72541044. Its totient is φ = 72467200.

The previous prime is 72504101. The next prime is 72504137. The reversal of 72504121 is 12140527.

It is a happy number.

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 18275625 + 54228496 = 4275^2 + 7364^2 .

It is a cyclic number.

It is not a de Polignac number, because 72504121 - 2¹⁵ = 72471353 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 72504092 and 72504101.

It is not an unprimeable number, because it can be changed into a prime (72504101) 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, 15340 + ... + 19501.

It is an arithmetic number, because the mean of its divisors is an integer number (18135261).

Almost surely, 2^72504121 is an apocalyptic number.

It is an amenable number.

72504121 is a deficient number, since it is larger than the sum of its proper divisors (36923).

72504121 is a wasteful number, since it uses less digits than its factorization.

72504121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36922.

The product of its (nonzero) digits is 560, while the sum is 22.

The square root of 72504121 is about 8514.9351729769. The cubic root of 72504121 is about 416.9854461467.

Adding to 72504121 its reverse (12140527), we get a palindrome (84644648).

The spelling of 72504121 in words is "seventy-two million, five hundred four thousand, one hundred twenty-one".