28055867720 has 128 divisors (see below), whose sum is σ = 68534294400. Its totient is φ = 10295341056.

The previous prime is 28055867713. The next prime is 28055867729. The reversal of 28055867720 is 2776855082.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (28055867729) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 25116602 + ... + 25117718.

It is an arithmetic number, because the mean of its divisors is an integer number (535424175).

Almost surely, 2^28055867720 is an apocalyptic number.

28055867720 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 28055867720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34267147200).

28055867720 is an abundant number, since it is smaller than the sum of its proper divisors (40478426680).

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

28055867720 is a wasteful number, since it uses less digits than its factorization.

28055867720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2047 (or 2043 counting only the distinct ones).

The product of its (nonzero) digits is 1881600, while the sum is 50.

The spelling of 28055867720 in words is "twenty-eight billion, fifty-five million, eight hundred sixty-seven thousand, seven hundred twenty".