20280663 has 24 divisors (see below), whose sum is σ = 31890768. Its totient is φ = 12344832.

The previous prime is 20280661. The next prime is 20280671. The reversal of 20280663 is 36608202.

It is not a de Polignac number, because 20280663 - 2¹ = 20280661 is a prime.

It is a super-2 number, since 2×20280663² = 822610583439138, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20280661) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10456 + ... + 12242.

It is an arithmetic number, because the mean of its divisors is an integer number (1328782).

Almost surely, 2^20280663 is an apocalyptic number.

20280663 is a deficient number, since it is larger than the sum of its proper divisors (11610105).

20280663 is a wasteful number, since it uses less digits than its factorization.

20280663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1903 (or 1900 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 20280663 is about 4503.4057112368. The cubic root of 20280663 is about 272.7055957620.

Adding to 20280663 its reverse (36608202), we get a palindrome (56888865).

The spelling of 20280663 in words is "twenty million, two hundred eighty thousand, six hundred sixty-three".