20209971149 has 2 divisors, whose sum is σ = 20209971150. Its totient is φ = 20209971148.

The previous prime is 20209971113. The next prime is 20209971163. The reversal of 20209971149 is 94117990202.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14961693124 + 5248278025 = 122318^2 + 72445^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20209971149 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20209971109) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10104985574 + 10104985575.

It is an arithmetic number, because the mean of its divisors is an integer number (10104985575).

Almost surely, 2^20209971149 is an apocalyptic number.

It is an amenable number.

20209971149 is a deficient number, since it is larger than the sum of its proper divisors (1).

20209971149 is an equidigital number, since it uses as much as digits as its factorization.

20209971149 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 81648, while the sum is 44.

The spelling of 20209971149 in words is "twenty billion, two hundred nine million, nine hundred seventy-one thousand, one hundred forty-nine".