20864256 has 72 divisors (see below), whose sum is σ = 63478464. Its totient is φ = 5959680.

The previous prime is 20864231. The next prime is 20864281. The reversal of 20864256 is 65246802.

It is an interprime number because it is at equal distance from previous prime (20864231) and next prime (20864281).

It is a congruent number.

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 7 ways as a sum of consecutive naturals, for example, 3436 + ... + 7316.

Almost surely, 2^20864256 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 20864256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31739232).

20864256 is an abundant number, since it is smaller than the sum of its proper divisors (42614208).

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

20864256 is an equidigital number, since it uses as much as digits as its factorization.

20864256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3907 (or 3893 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 33.

The square root of 20864256 is about 4567.7407982503. The cubic root of 20864256 is about 275.2966759677.

The spelling of 20864256 in words is "twenty million, eight hundred sixty-four thousand, two hundred fifty-six".