20843136 has 128 divisors (see below), whose sum is σ = 63566400. Its totient is φ = 6718464.

The previous prime is 20843117. The next prime is 20843143. The reversal of 20843136 is 63134802.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (27).

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, 127791 + ... + 127953.

Almost surely, 2^20843136 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 20843136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31783200).

20843136 is an abundant number, since it is smaller than the sum of its proper divisors (42723264).

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

20843136 is a wasteful number, since it uses less digits than its factorization.

20843136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 223 (or 205 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 20843136 is about 4565.4283479209. The cubic root of 20843136 is about 275.2037542304.

Adding to 20843136 its reverse (63134802), we get a palindrome (83977938).

The spelling of 20843136 in words is "twenty million, eight hundred forty-three thousand, one hundred thirty-six".