20421588 has 48 divisors (see below), whose sum is σ = 52738560. Its totient is φ = 6098400.

The previous prime is 20421571. The next prime is 20421593. The reversal of 20421588 is 88512402.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8283 + ... + 10461.

It is an arithmetic number, because the mean of its divisors is an integer number (1098720).

Almost surely, 2^20421588 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 20421588, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26369280).

20421588 is an abundant number, since it is smaller than the sum of its proper divisors (32316972).

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

20421588 is a wasteful number, since it uses less digits than its factorization.

20421588 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2268 (or 2266 counting only the distinct ones).

The product of its (nonzero) digits is 5120, while the sum is 30.

The square root of 20421588 is about 4519.0251161063. The cubic root of 20421588 is about 273.3357915041.

The spelling of 20421588 in words is "twenty million, four hundred twenty-one thousand, five hundred eighty-eight".