21406658253289 has 3 divisors (see below), whose sum is σ = 21406662880023. Its totient is φ = 21406653626556.

The previous prime is 21406658253259. The next prime is 21406658253311. The reversal of 21406658253289 is 98235285660412.

The square root of 21406658253289 is 4626733.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 12093736536025 + 9312921717264 = 3477605^2 + 3051708^2 .

It is not a de Polignac number, because 21406658253289 - 2²³ = 21406649864681 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21406658253259) 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 2 ways as a sum of consecutive naturals, for example, 2313367 + ... + 6940099.

It is an arithmetic number, because the mean of its divisors is an integer number (7135554293341).

Almost surely, 2^{21406658253289} is an apocalyptic number.

21406658253289 is the 4626733-rd square number.

21406658253289 is the 2313367-th centered octagonal number.

It is an amenable number.

21406658253289 is a deficient number, since it is larger than the sum of its proper divisors (4626734).

21406658253289 is an frugal number, since it uses more digits than its factorization.

21406658253289 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9253466 (or 4626733 counting only the distinct ones).

The product of its (nonzero) digits is 49766400, while the sum is 61.

The spelling of 21406658253289 in words is "twenty-one trillion, four hundred six billion, six hundred fifty-eight million, two hundred fifty-three thousand, two hundred eighty-nine".