20994271289 has 2 divisors, whose sum is σ = 20994271290. Its totient is φ = 20994271288.

The previous prime is 20994271219. The next prime is 20994271307. The reversal of 20994271289 is 98217249902.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20027061289 + 967210000 = 141517^2 + 31100^2 .

It is a cyclic number.

It is not a de Polignac number, because 20994271289 - 2²⁰ = 20993222713 is a prime.

It is a super-2 number, since 2×20994271289² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20994271289.

It is not a weakly prime, because it can be changed into another prime (20994271219) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10497135644 + 10497135645.

It is an arithmetic number, because the mean of its divisors is an integer number (10497135645).

Almost surely, 2^20994271289 is an apocalyptic number.

It is an amenable number.

20994271289 is a deficient number, since it is larger than the sum of its proper divisors (1).

20994271289 is an equidigital number, since it uses as much as digits as its factorization.

20994271289 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1306368, while the sum is 53.

Subtracting from 20994271289 its sum of digits (53), we obtain a square (20994271236 = 144894²).

The spelling of 20994271289 in words is "twenty billion, nine hundred ninety-four million, two hundred seventy-one thousand, two hundred eighty-nine".