20784481 has 9 divisors (see below), whose sum is σ = 21457299. Its totient is φ = 20132544.

The previous prime is 20784451. The next prime is 20784493. The reversal of 20784481 is 18448702.

20784481 = T₂₂₃ + T₂₂₄ + ... + T₅₁₃.

The square root of 20784481 is 4559.

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., 9333025 + 11451456 = 3055^2 + 3384^2 .

It is not a de Polignac number, because 20784481 - 2⁹ = 20783969 is a prime.

It is a super-2 number, since 2×20784481² = 863989300878722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20784451) 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, 214225 + ... + 214321.

Almost surely, 2^20784481 is an apocalyptic number.

20784481 is the 4559-th square number.

20784481 is the 2280-th centered octagonal number.

It is an amenable number.

20784481 is a deficient number, since it is larger than the sum of its proper divisors (672818).

20784481 is an frugal number, since it uses more digits than its factorization.

20784481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 288 (or 144 counting only the distinct ones).

The product of its (nonzero) digits is 14336, while the sum is 34.

The cubic root of 20784481 is about 274.9453599431.

The spelling of 20784481 in words is "twenty million, seven hundred eighty-four thousand, four hundred eighty-one".