21130020689 has 2 divisors, whose sum is σ = 21130020690. Its totient is φ = 21130020688.

The previous prime is 21130020671. The next prime is 21130020713. The reversal of 21130020689 is 98602003112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14401920064 + 6728100625 = 120008^2 + 82025^2 .

It is a cyclic number.

It is not a de Polignac number, because 21130020689 - 2⁸ = 21130020433 is a prime.

It is not a weakly prime, because it can be changed into another prime (21130020619) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10565010344 + 10565010345.

It is an arithmetic number, because the mean of its divisors is an integer number (10565010345).

Almost surely, 2^21130020689 is an apocalyptic number.

It is an amenable number.

21130020689 is a deficient number, since it is larger than the sum of its proper divisors (1).

21130020689 is an equidigital number, since it uses as much as digits as its factorization.

21130020689 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5184, while the sum is 32.

The spelling of 21130020689 in words is "twenty-one billion, one hundred thirty million, twenty thousand, six hundred eighty-nine".