21211202201989 has 2 divisors, whose sum is σ = 21211202201990. Its totient is φ = 21211202201988.

The previous prime is 21211202201963. The next prime is 21211202201999. The reversal of 21211202201989 is 98910220211212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20996052801025 + 215149400964 = 4582145^2 + 463842^2 .

It is a cyclic number.

It is not a de Polignac number, because 21211202201989 - 2³⁹ = 20661446388101 is a prime.

It is a super-2 number, since 2×21211202201989² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21211202201999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605601100994 + 10605601100995.

It is an arithmetic number, because the mean of its divisors is an integer number (10605601100995).

Almost surely, 2^{21211202201989} is an apocalyptic number.

It is an amenable number.

21211202201989 is a deficient number, since it is larger than the sum of its proper divisors (1).

21211202201989 is an equidigital number, since it uses as much as digits as its factorization.

21211202201989 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 40.

The spelling of 21211202201989 in words is "twenty-one trillion, two hundred eleven billion, two hundred two million, two hundred one thousand, nine hundred eighty-nine".