20438420256 has 60 divisors (see below), whose sum is σ = 60108833862. Its totient is φ = 6812805888.

The previous prime is 20438420179. The next prime is 20438420267. The reversal of 20438420256 is 65202483402.

20438420256 is a `hidden beast` number, since 2 + 0 + 4 + 384 + 20 + 256 = 666.

It can be written as a sum of positive squares in only one way, i.e., 16973920656 + 3464499600 = 130284^2 + 58860^2 .

It is a super-2 number, since 2×20438420256² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 20438420256.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 3940005 + ... + 3945188.

Almost surely, 2^20438420256 is an apocalyptic number.

It is an amenable number.

20438420256 is an abundant number, since it is smaller than the sum of its proper divisors (39670413606).

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

20438420256 is an equidigital number, since it uses as much as digits as its factorization.

20438420256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7885215 (or 7885198 counting only the distinct ones).

The product of its (nonzero) digits is 92160, while the sum is 36.

The spelling of 20438420256 in words is "twenty billion, four hundred thirty-eight million, four hundred twenty thousand, two hundred fifty-six".