20449 has 9 divisors (see below), whose sum is σ = 24339. Its totient is φ = 17160.

The previous prime is 20443. The next prime is 20477. The reversal of 20449 is 94402.

20449 = T₁₄₂ + T₁₄₃.

20449 = 7² + 8² + ... + 39².

The square root of 20449 is 143.

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

It can be written as a sum of positive squares in only one way, i.e., 3025 + 17424 = 55^2 + 132^2 .

It is not a de Polignac number, because 20449 - 2³ = 20441 is a prime.

It is a Duffinian number.

20449 is a lucky number.

It is a nialpdrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (20441) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 1567 + ... + 1579.

2²⁰⁴⁴⁹ is an apocalyptic number.

20449 is the 143-rd square number.

20449 is the 72-nd centered octagonal number.

It is an amenable number.

20449 is a deficient number, since it is larger than the sum of its proper divisors (3890).

20449 is a wasteful number, since it uses less digits than its factorization.

20449 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48 (or 24 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 19.

The cubic root of 20449 is about 27.3458036825.

It can be divided in two parts, 204 and 49, that added together give a triangular number (253 = T₂₂).

The spelling of 20449 in words is "twenty thousand, four hundred forty-nine".