20280205 has 12 divisors (see below), whose sum is σ = 26750556. Its totient is φ = 14748800.

The previous prime is 20280191. The next prime is 20280217. The reversal of 20280205 is 50208202.

It can be written as a sum of positive squares in 2 ways, for example, as 6456681 + 13823524 = 2541^2 + 3718^2 .

It is not a de Polignac number, because 20280205 - 2¹⁷ = 20149133 is a prime.

It is a super-2 number, since 2×20280205² = 822573429684050, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 16156 + ... + 17365.

It is an arithmetic number, because the mean of its divisors is an integer number (2229213).

Almost surely, 2^20280205 is an apocalyptic number.

It is an amenable number.

20280205 is a deficient number, since it is larger than the sum of its proper divisors (6470351).

20280205 is a wasteful number, since it uses less digits than its factorization.

20280205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33548 (or 33537 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 19.

The square root of 20280205 is about 4503.3548605456. The cubic root of 20280205 is about 272.7035429017.

Adding to 20280205 its reverse (50208202), we get a palindrome (70488407).

The spelling of 20280205 in words is "twenty million, two hundred eighty thousand, two hundred five".