20438261928 has 128 divisors (see below), whose sum is σ = 65313792000. Its totient is φ = 5800766400.

The previous prime is 20438261923. The next prime is 20438261933. The reversal of 20438261928 is 82916283402.

20438261928 is a `hidden beast` number, since 2 + 0 + 4 + 3 + 8 + 2 + 619 + 28 = 666.

It is an interprime number because it is at equal distance from previous prime (20438261923) and next prime (20438261933).

It is not an unprimeable number, because it can be changed into a prime (20438261923) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 183553 + ... + 273071.

It is an arithmetic number, because the mean of its divisors is an integer number (510264000).

Almost surely, 2^20438261928 is an apocalyptic number.

20438261928 is a gapful number since it is divisible by the number (28) 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 20438261928, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32656896000).

20438261928 is an abundant number, since it is smaller than the sum of its proper divisors (44875530072).

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

20438261928 is a wasteful number, since it uses less digits than its factorization.

20438261928 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89692 (or 89682 counting only the distinct ones).

The product of its (nonzero) digits is 331776, while the sum is 45.

The spelling of 20438261928 in words is "twenty billion, four hundred thirty-eight million, two hundred sixty-one thousand, nine hundred twenty-eight".