28781447808 has 64 divisors (see below), whose sum is σ = 79774689600. Its totient is φ = 9176690688.

The previous prime is 28781447803. The next prime is 28781447819. The reversal of 28781447808 is 80874418782.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (64).

It is not an unprimeable number, because it can be changed into a prime (28781447803) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1620553 + ... + 1638216.

It is an arithmetic number, because the mean of its divisors is an integer number (1246479525).

Almost surely, 2^28781447808 is an apocalyptic number.

It is an amenable number.

28781447808 is an abundant number, since it is smaller than the sum of its proper divisors (50993241792).

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

28781447808 is a wasteful number, since it uses less digits than its factorization.

28781447808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3258809 (or 3258797 counting only the distinct ones).

The product of its (nonzero) digits is 6422528, while the sum is 57.

The spelling of 28781447808 in words is "twenty-eight billion, seven hundred eighty-one million, four hundred forty-seven thousand, eight hundred eight".