20636420 has 48 divisors (see below), whose sum is σ = 49824768. Its totient is φ = 7032960.

The previous prime is 20636411. The next prime is 20636449. The reversal of 20636420 is 2463602.

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 15 ways as a sum of consecutive naturals, for example, 30890 + ... + 31550.

It is an arithmetic number, because the mean of its divisors is an integer number (1038016).

Almost surely, 2^20636420 is an apocalyptic number.

20636420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20636420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24912384).

20636420 is an abundant number, since it is smaller than the sum of its proper divisors (29188348).

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

20636420 is a wasteful number, since it uses less digits than its factorization.

20636420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 900 (or 898 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 23.

The square root of 20636420 is about 4542.7326577733. The cubic root of 20636420 is about 274.2909336288.

The spelling of 20636420 in words is "twenty million, six hundred thirty-six thousand, four hundred twenty".