21891283489 has 2 divisors, whose sum is σ = 21891283490. Its totient is φ = 21891283488.

The previous prime is 21891283451. The next prime is 21891283493. The reversal of 21891283489 is 98438219812.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15936537600 + 5954745889 = 126240^2 + 77167^2 .

It is a cyclic number.

It is not a de Polignac number, because 21891283489 - 2³¹ = 19743799841 is a prime.

It is not a weakly prime, because it can be changed into another prime (21891283189) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10945641744 + 10945641745.

It is an arithmetic number, because the mean of its divisors is an integer number (10945641745).

Almost surely, 2^21891283489 is an apocalyptic number.

It is an amenable number.

21891283489 is a deficient number, since it is larger than the sum of its proper divisors (1).

21891283489 is an equidigital number, since it uses as much as digits as its factorization.

21891283489 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1990656, while the sum is 55.

The spelling of 21891283489 in words is "twenty-one billion, eight hundred ninety-one million, two hundred eighty-three thousand, four hundred eighty-nine".