20212420 has 24 divisors (see below), whose sum is σ = 43911000. Its totient is φ = 7805952.

The previous prime is 20212417. The next prime is 20212421. The reversal of 20212420 is 2421202.

It can be written as a sum of positive squares in 4 ways, for example, as 16384 + 20196036 = 128^2 + 4494^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 20212420.

It is not an unprimeable number, because it can be changed into a prime (20212421) 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 7 ways as a sum of consecutive naturals, for example, 16845 + ... + 18004.

It is an arithmetic number, because the mean of its divisors is an integer number (1829625).

Almost surely, 2^20212420 is an apocalyptic number.

20212420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20212420 is an abundant number, since it is smaller than the sum of its proper divisors (23698580).

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

20212420 is a wasteful number, since it uses less digits than its factorization.

20212420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34887 (or 34885 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 13.

The square root of 20212420 is about 4495.8225053932. The cubic root of 20212420 is about 272.3993736702.

Adding to 20212420 its reverse (2421202), we get a palindrome (22633622).

The spelling of 20212420 in words is "twenty million, two hundred twelve thousand, four hundred twenty".