28781444037888 has 54 divisors (see below), whose sum is σ = 82983998593314. Its totient is φ = 9593814678528.

The previous prime is 28781444037887. The next prime is 28781444037889. The reversal of 28781444037888 is 88873044418782.

28781444037888 is a `hidden beast` number, since 2 + 8 + 7 + 8 + 144 + 403 + 78 + 8 + 8 = 666.

It is an interprime number because it is at equal distance from previous prime (28781444037887) and next prime (28781444037889).

It can be written as a sum of positive squares in only one way, i.e., 21393659107584 + 7387784930304 = 4625328^2 + 2718048^2 .

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28781444037887) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6245970795 + ... + 6245975402.

It is an arithmetic number, because the mean of its divisors is an integer number (1536740714691).

Almost surely, 2^{28781444037888} is an apocalyptic number.

It is an amenable number.

28781444037888 is an abundant number, since it is smaller than the sum of its proper divisors (54202554555426).

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

28781444037888 is a wasteful number, since it uses less digits than its factorization.

28781444037888 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12491946219 (or 12491946202 counting only the distinct ones).

The product of its (nonzero) digits is 616562688, while the sum is 72.

The spelling of 28781444037888 in words is "twenty-eight trillion, seven hundred eighty-one billion, four hundred forty-four million, thirty-seven thousand, eight hundred eighty-eight".