20421376 has 36 divisors (see below), whose sum is σ = 41055784. Its totient is φ = 10137600.

The previous prime is 20421367. The next prime is 20421383. The reversal of 20421376 is 67312402.

It is a self number, because there is not a number n which added to its sum of digits gives 20421376.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 61531 + ... + 61861.

Almost surely, 2^20421376 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20421376, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20527892).

20421376 is an abundant number, since it is smaller than the sum of its proper divisors (20634408).

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

20421376 is an equidigital number, since it uses as much as digits as its factorization.

20421376 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 588 (or 574 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 25.

The square root of 20421376 is about 4519.0016596589. The cubic root of 20421376 is about 273.3348456523.

Adding to 20421376 its reverse (67312402), we get a palindrome (87733778).

The spelling of 20421376 in words is "twenty million, four hundred twenty-one thousand, three hundred seventy-six".