20421142 has 12 divisors (see below), whose sum is σ = 35632980. Its totient is φ = 8751876.

The previous prime is 20421103. The next prime is 20421179. The reversal of 20421142 is 24112402.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 104092 + ... + 104287.

It is an arithmetic number, because the mean of its divisors is an integer number (2969415).

Almost surely, 2^20421142 is an apocalyptic number.

20421142 is a deficient number, since it is larger than the sum of its proper divisors (15211838).

20421142 is a wasteful number, since it uses less digits than its factorization.

20421142 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 208395 (or 208388 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

The square root of 20421142 is about 4518.9757689105. The cubic root of 20421142 is about 273.3338016384. Note that the first 3 decimals are identical.

Adding to 20421142 its reverse (24112402), we get a palindrome (44533544).

The spelling of 20421142 in words is "twenty million, four hundred twenty-one thousand, one hundred forty-two".