1980517109 has 2 divisors, whose sum is σ = 1980517110. Its totient is φ = 1980517108.

The previous prime is 1980517087. The next prime is 1980517159. The reversal of 1980517109 is 9017150891.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1980517009 + 100 = 44503^2 + 10^2 .

It is a cyclic number.

It is not a de Polignac number, because 1980517109 - 2¹⁶ = 1980451573 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 (1980517159) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 990258554 + 990258555.

It is an arithmetic number, because the mean of its divisors is an integer number (990258555).

Almost surely, 2^1980517109 is an apocalyptic number.

It is an amenable number.

1980517109 is a deficient number, since it is larger than the sum of its proper divisors (1).

1980517109 is an equidigital number, since it uses as much as digits as its factorization.

1980517109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 22680, while the sum is 41.

The square root of 1980517109 is about 44503.0011235197. The cubic root of 1980517109 is about 1255.8165422083.

The spelling of 1980517109 in words is "one billion, nine hundred eighty million, five hundred seventeen thousand, one hundred nine".