20404242 has 24 divisors (see below), whose sum is σ = 45405516. Its totient is φ = 6617376.

The previous prime is 20404213. The next prime is 20404249. The reversal of 20404242 is 24240402.

20404242 is a `hidden beast` number, since 20 + 404 + 242 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 15515721 + 4888521 = 3939^2 + 2211^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (20404249) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 14653 + ... + 15984.

Almost surely, 2^20404242 is an apocalyptic number.

20404242 is an abundant number, since it is smaller than the sum of its proper divisors (25001274).

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

20404242 is a wasteful number, since it uses less digits than its factorization.

20404242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30682 (or 30679 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 18.

The square root of 20404242 is about 4517.1054891379. The cubic root of 20404242 is about 273.2583795405.

Adding to 20404242 its reverse (24240402), we get a palindrome (44644644).

The spelling of 20404242 in words is "twenty million, four hundred four thousand, two hundred forty-two".