21384090289 has 9 divisors (see below), whose sum is σ = 21505415617. Its totient is φ = 21263448064.

The previous prime is 21384090269. The next prime is 21384090317. The reversal of 21384090289 is 98209048312.

The square root of 21384090289 is 146233.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 1786330225 + 19597760064 = 42265^2 + 139992^2 .

It is not a de Polignac number, because 21384090289 - 2²⁹ = 20847219377 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21384090269) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 37581597 + ... + 37582165.

Almost surely, 2^21384090289 is an apocalyptic number.

21384090289 is the 146233-rd square number.

21384090289 is the 73117-th centered octagonal number.

It is an amenable number.

21384090289 is a deficient number, since it is larger than the sum of its proper divisors (121325328).

21384090289 is an frugal number, since it uses more digits than its factorization.

21384090289 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1652 (or 826 counting only the distinct ones).

The product of its (nonzero) digits is 248832, while the sum is 46.

The spelling of 21384090289 in words is "twenty-one billion, three hundred eighty-four million, ninety thousand, two hundred eighty-nine".