288072721 has 4 divisors (see below), whose sum is σ = 290715700. Its totient is φ = 285429744.

The previous prime is 288072709. The next prime is 288072727. The reversal of 288072721 is 127270882.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 127270882 = 2 ⋅63635441.

It can be written as a sum of positive squares in 2 ways, for example, as 83010321 + 205062400 = 9111^2 + 14320^2 .

It is a cyclic number.

It is not a de Polignac number, because 288072721 - 2⁷ = 288072593 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (288072727) 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, 1321326 + ... + 1321543.

It is an arithmetic number, because the mean of its divisors is an integer number (72678925).

Almost surely, 2^288072721 is an apocalyptic number.

It is an amenable number.

288072721 is a deficient number, since it is larger than the sum of its proper divisors (2642979).

288072721 is a wasteful number, since it uses less digits than its factorization.

288072721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2642978.

The product of its (nonzero) digits is 25088, while the sum is 37.

The square root of 288072721 is about 16972.7051762528. The cubic root of 288072721 is about 660.4410283076.

The spelling of 288072721 in words is "two hundred eighty-eight million, seventy-two thousand, seven hundred twenty-one".