20421030 has 64 divisors (see below), whose sum is σ = 57231360. Its totient is φ = 4566144.

The previous prime is 20421013. The next prime is 20421043. The reversal of 20421030 is 3012402.

It is a junction number, because it is equal to n+sod(n) for n = 20420997 and 20421015.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 8836 + ... + 10904.

It is an arithmetic number, because the mean of its divisors is an integer number (894240).

Almost surely, 2^20421030 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20421030, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28615680).

20421030 is an abundant number, since it is smaller than the sum of its proper divisors (36810330).

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

20421030 is a wasteful number, since it uses less digits than its factorization.

20421030 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2133.

The product of its (nonzero) digits is 48, while the sum is 12.

The square root of 20421030 is about 4518.9633767049. The cubic root of 20421030 is about 273.3333019367. Note that the first 4 decimals are identical.

Adding to 20421030 its reverse (3012402), we get a palindrome (23433432).

The spelling of 20421030 in words is "twenty million, four hundred twenty-one thousand, thirty".