20421368 has 32 divisors (see below), whose sum is σ = 42174000. Its totient is φ = 9192960.

The previous prime is 20421367. The next prime is 20421383. The reversal of 20421368 is 86312402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20421367) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8528 + ... + 10656.

Almost surely, 2^20421368 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 20421368, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21087000).

20421368 is an abundant number, since it is smaller than the sum of its proper divisors (21752632).

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

20421368 is a wasteful number, since it uses less digits than its factorization.

20421368 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2255 (or 2251 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 26.

The square root of 20421368 is about 4519.0007745076. Note that the first 3 decimals coincide. The cubic root of 20421368 is about 273.3348099596.

The spelling of 20421368 in words is "twenty million, four hundred twenty-one thousand, three hundred sixty-eight".