20042240 has 40 divisors (see below), whose sum is σ = 48060540. Its totient is φ = 8015872.

The previous prime is 20042173. The next prime is 20042249. The reversal of 20042240 is 4224002.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 18524416 + 1517824 = 4304^2 + 1232^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is not an unprimeable number, because it can be changed into a prime (20042249) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1355 + ... + 6474.

Almost surely, 2^20042240 is an apocalyptic number.

20042240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20042240 is an abundant number, since it is smaller than the sum of its proper divisors (28018300).

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

20042240 is an frugal number, since it uses more digits than its factorization.

20042240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7852 (or 7836 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 14.

The square root of 20042240 is about 4476.8560396778. The cubic root of 20042240 is about 271.6327222864.

Adding to 20042240 its reverse (4224002), we get a palindrome (24266242).

The spelling of 20042240 in words is "twenty million, forty-two thousand, two hundred forty".