20420404 has 6 divisors (see below), whose sum is σ = 35735714. Its totient is φ = 10210200.

The previous prime is 20420377. The next prime is 20420443. The reversal of 20420404 is 40402402.

It can be written as a sum of positive squares in only one way, i.e., 18079504 + 2340900 = 4252^2 + 1530^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2552547 + ... + 2552554.

Almost surely, 2^20420404 is an apocalyptic number.

It is an amenable number.

20420404 is a deficient number, since it is larger than the sum of its proper divisors (15315310).

20420404 is a wasteful number, since it uses less digits than its factorization.

20420404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5105105 (or 5105103 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 16.

The square root of 20420404 is about 4518.8941125014. The cubic root of 20420404 is about 273.3305089271.

Adding to 20420404 its reverse (40402402), we get a palindrome (60822806).

The spelling of 20420404 in words is "twenty million, four hundred twenty thousand, four hundred four".