722128289 has 8 divisors (see below), whose sum is σ = 730755360. Its totient is φ = 713512800.

The previous prime is 722128243. The next prime is 722128313. The reversal of 722128289 is 982821227.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-722128289 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (722128489) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 241574 + ... + 244544.

It is an arithmetic number, because the mean of its divisors is an integer number (91344420).

Almost surely, 2^722128289 is an apocalyptic number.

It is an amenable number.

722128289 is a deficient number, since it is larger than the sum of its proper divisors (8627071).

722128289 is a wasteful number, since it uses less digits than its factorization.

722128289 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5791.

The product of its digits is 64512, while the sum is 41.

The square root of 722128289 is about 26872.4447901563. Note that the first 3 decimals coincide. The cubic root of 722128289 is about 897.1632032122.

The spelling of 722128289 in words is "seven hundred twenty-two million, one hundred twenty-eight thousand, two hundred eighty-nine".