20780169349 has 4 divisors (see below), whose sum is σ = 20781059436. Its totient is φ = 20779279264.

The previous prime is 20780169343. The next prime is 20780169353. The reversal of 20780169349 is 94396108702.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 5181408324 + 15598761025 = 71982^2 + 124895^2 .

It is a cyclic number.

It is not a de Polignac number, because 20780169349 - 2³ = 20780169341 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20780169341) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 409054 + ... + 457039.

It is an arithmetic number, because the mean of its divisors is an integer number (5195264859).

Almost surely, 2^20780169349 is an apocalyptic number.

It is an amenable number.

20780169349 is a deficient number, since it is larger than the sum of its proper divisors (890087).

20780169349 is an equidigital number, since it uses as much as digits as its factorization.

20780169349 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 890086.

The product of its (nonzero) digits is 653184, while the sum is 49.

The spelling of 20780169349 in words is "twenty billion, seven hundred eighty million, one hundred sixty-nine thousand, three hundred forty-nine".