1989522569 has 2 divisors, whose sum is σ = 1989522570. Its totient is φ = 1989522568.

The previous prime is 1989522541. The next prime is 1989522593. The reversal of 1989522569 is 9652259891.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1902006544 + 87516025 = 43612^2 + 9355^2 .

It is an emirp because it is prime and its reverse (9652259891) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1989522569 - 2¹² = 1989518473 is a prime.

It is a super-2 number, since 2×1989522569² = 7916400105120719522, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (1989525569) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 994761284 + 994761285.

It is an arithmetic number, because the mean of its divisors is an integer number (994761285).

Almost surely, 2^1989522569 is an apocalyptic number.

It is an amenable number.

1989522569 is a deficient number, since it is larger than the sum of its proper divisors (1).

1989522569 is an equidigital number, since it uses as much as digits as its factorization.

1989522569 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3499200, while the sum is 56.

The square root of 1989522569 is about 44604.0644896852. The cubic root of 1989522569 is about 1257.7170740909.

The spelling of 1989522569 in words is "one billion, nine hundred eighty-nine million, five hundred twenty-two thousand, five hundred sixty-nine".