21713072189 has 2 divisors, whose sum is σ = 21713072190. Its totient is φ = 21713072188.

The previous prime is 21713072123. The next prime is 21713072239. The reversal of 21713072189 is 98127031712.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18675408964 + 3037663225 = 136658^2 + 55115^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21713072189 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21713072989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10856536094 + 10856536095.

It is an arithmetic number, because the mean of its divisors is an integer number (10856536095).

Almost surely, 2^21713072189 is an apocalyptic number.

It is an amenable number.

21713072189 is a deficient number, since it is larger than the sum of its proper divisors (1).

21713072189 is an equidigital number, since it uses as much as digits as its factorization.

21713072189 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 42336, while the sum is 41.

The spelling of 21713072189 in words is "twenty-one billion, seven hundred thirteen million, seventy-two thousand, one hundred eighty-nine".