201021201989 has 2 divisors, whose sum is σ = 201021201990. Its totient is φ = 201021201988.

The previous prime is 201021201961. The next prime is 201021202007. The reversal of 201021201989 is 989102120102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 197833696225 + 3187505764 = 444785^2 + 56458^2 .

It is a cyclic number.

It is not a de Polignac number, because 201021201989 - 2²⁴ = 201004424773 is a prime.

It is a super-2 number, since 2×201021201989² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (201021231989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100510600994 + 100510600995.

It is an arithmetic number, because the mean of its divisors is an integer number (100510600995).

Almost surely, 2^201021201989 is an apocalyptic number.

It is an amenable number.

201021201989 is a deficient number, since it is larger than the sum of its proper divisors (1).

201021201989 is an equidigital number, since it uses as much as digits as its factorization.

201021201989 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 35.

The spelling of 201021201989 in words is "two hundred one billion, twenty-one million, two hundred one thousand, nine hundred eighty-nine".