20983550449 has 9 divisors (see below), whose sum is σ = 22293100641. Its totient is φ = 19746906240.

The previous prime is 20983550411. The next prime is 20983550453. The reversal of 20983550449 is 94405538902.

The square root of 20983550449 is 144857.

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

It can be written as a sum of positive squares in 4 ways, for example, as 1598000625 + 19385549824 = 39975^2 + 139232^2 .

It is not a de Polignac number, because 20983550449 - 2⁷ = 20983550321 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20983550479) 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 8 ways as a sum of consecutive naturals, for example, 2458309 + ... + 2466829.

Almost surely, 2^20983550449 is an apocalyptic number.

20983550449 is the 144857-th square number.

20983550449 is the 72429-th centered octagonal number.

It is an amenable number.

20983550449 is a deficient number, since it is larger than the sum of its proper divisors (1309550192).

20983550449 is an frugal number, since it uses more digits than its factorization.

20983550449 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17076 (or 8538 counting only the distinct ones).

The product of its (nonzero) digits is 1555200, while the sum is 49.

Multiplying 20983550449 by its sum of digits (49), we get a square (1028193972001 = 1013999²).

The spelling of 20983550449 in words is "twenty billion, nine hundred eighty-three million, five hundred fifty thousand, four hundred forty-nine".