28087781138648 has 128 divisors (see below), whose sum is σ = 66288934379520. Its totient is φ = 10838475000960.

The previous prime is 28087781138647. The next prime is 28087781138653. The reversal of 28087781138648 is 84683118778082.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28087781138647) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 294117515 + ... + 294212997.

It is an arithmetic number, because the mean of its divisors is an integer number (517882299840).

Almost surely, 2^{28087781138648} is an apocalyptic number.

28087781138648 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 28087781138648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33144467189760).

28087781138648 is an abundant number, since it is smaller than the sum of its proper divisors (38201153240872).

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

28087781138648 is a wasteful number, since it uses less digits than its factorization.

28087781138648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 100077 (or 100073 counting only the distinct ones).

The product of its (nonzero) digits is 231211008, while the sum is 71.

The spelling of 28087781138648 in words is "twenty-eight trillion, eighty-seven billion, seven hundred eighty-one million, one hundred thirty-eight thousand, six hundred forty-eight".