21222201989 has 2 divisors, whose sum is σ = 21222201990. Its totient is φ = 21222201988.

The previous prime is 21222201947. The next prime is 21222202021. The reversal of 21222201989 is 98910222212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17208979489 + 4013222500 = 131183^2 + 63350^2 .

It is a cyclic number.

It is not a de Polignac number, because 21222201989 - 2⁸ = 21222201733 is a prime.

It is a super-2 number, since 2×21222201989² (a number of 21 digits) contains 22 as substring.

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 (21222201289) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10611100994 + 10611100995.

It is an arithmetic number, because the mean of its divisors is an integer number (10611100995).

Almost surely, 2^21222201989 is an apocalyptic number.

It is an amenable number.

21222201989 is a deficient number, since it is larger than the sum of its proper divisors (1).

21222201989 is an equidigital number, since it uses as much as digits as its factorization.

21222201989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 20736, while the sum is 38.

The spelling of 21222201989 in words is "twenty-one billion, two hundred twenty-two million, two hundred one thousand, nine hundred eighty-nine".