21828521707 has 2 divisors, whose sum is σ = 21828521708. Its totient is φ = 21828521706.

The previous prime is 21828521683. The next prime is 21828521719. The reversal of 21828521707 is 70712582812.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21828521707 - 2¹¹ = 21828519659 is a prime.

It is not a weakly prime, because it can be changed into another prime (21828521777) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10914260853 + 10914260854.

It is an arithmetic number, because the mean of its divisors is an integer number (10914260854).

Almost surely, 2^21828521707 is an apocalyptic number.

21828521707 is a deficient number, since it is larger than the sum of its proper divisors (1).

21828521707 is an equidigital number, since it uses as much as digits as its factorization.

21828521707 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 125440, while the sum is 43.

The spelling of 21828521707 in words is "twenty-one billion, eight hundred twenty-eight million, five hundred twenty-one thousand, seven hundred seven".