21628214689 has 2 divisors, whose sum is σ = 21628214690. Its totient is φ = 21628214688.

The previous prime is 21628214669. The next prime is 21628214731. The reversal of 21628214689 is 98641282612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11445790225 + 10182424464 = 106985^2 + 100908^2 .

It is a cyclic number.

It is not a de Polignac number, because 21628214689 - 2¹⁵ = 21628181921 is a prime.

It is not a weakly prime, because it can be changed into another prime (21628214659) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10814107344 + 10814107345.

It is an arithmetic number, because the mean of its divisors is an integer number (10814107345).

Almost surely, 2^21628214689 is an apocalyptic number.

It is an amenable number.

21628214689 is a deficient number, since it is larger than the sum of its proper divisors (1).

21628214689 is an equidigital number, since it uses as much as digits as its factorization.

21628214689 is an evil number, because the sum of its binary digits is even.

The product of its digits is 663552, while the sum is 49.

The spelling of 21628214689 in words is "twenty-one billion, six hundred twenty-eight million, two hundred fourteen thousand, six hundred eighty-nine".