20291051784481 has 3 divisors (see below), whose sum is σ = 20291056289041. Its totient is φ = 20291047279922.

The previous prime is 20291051784449. The next prime is 20291051784527. The reversal of 20291051784481 is 18448715019202.

It is a happy number.

The square root of 20291051784481 is 4504559.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 20291051784481 - 2⁵ = 20291051784449 is a prime.

It is a super-2 number, since 2×20291051784481² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20291051784581) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 2252280 + ... + 6756838.

Almost surely, 2^{20291051784481} is an apocalyptic number.

20291051784481 is the 4504559-th square number.

20291051784481 is the 2252280-th centered octagonal number.

It is an amenable number.

20291051784481 is a deficient number, since it is larger than the sum of its proper divisors (4504560).

20291051784481 is an frugal number, since it uses more digits than its factorization.

20291051784481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9009118 (or 4504559 counting only the distinct ones).

The product of its (nonzero) digits is 1290240, while the sum is 52.

The spelling of 20291051784481 in words is "twenty trillion, two hundred ninety-one billion, fifty-one million, seven hundred eighty-four thousand, four hundred eighty-one".