20405224 has 16 divisors (see below), whose sum is σ = 43725600. Its totient is φ = 8745072.

The previous prime is 20405213. The next prime is 20405233. The reversal of 20405224 is 42250402.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 182134 + ... + 182245.

It is an arithmetic number, because the mean of its divisors is an integer number (2732850).

Almost surely, 2^20405224 is an apocalyptic number.

It is an amenable number.

20405224 is an abundant number, since it is smaller than the sum of its proper divisors (23320376).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20405224 is a wasteful number, since it uses less digits than its factorization.

20405224 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 364392 (or 364388 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 19.

The square root of 20405224 is about 4517.2141857565. The cubic root of 20405224 is about 273.2627631947.

Adding to 20405224 its reverse (42250402), we get a palindrome (62655626).

The spelling of 20405224 in words is "twenty million, four hundred five thousand, two hundred twenty-four".