28708631388 has 144 divisors (see below), whose sum is σ = 76437859680. Its totient is φ = 9420364800.

The previous prime is 28708631387. The next prime is 28708631389. The reversal of 28708631388 is 88313680782.

It is an interprime number because it is at equal distance from previous prime (28708631387) and next prime (28708631389).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28708631387) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 24308158 + ... + 24309338.

It is an arithmetic number, because the mean of its divisors is an integer number (530818470).

Almost surely, 2^28708631388 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28708631388, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38218929840).

28708631388 is an abundant number, since it is smaller than the sum of its proper divisors (47729228292).

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

28708631388 is a wasteful number, since it uses less digits than its factorization.

28708631388 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1570 (or 1556 counting only the distinct ones).

The product of its (nonzero) digits is 3096576, while the sum is 54.

The spelling of 28708631388 in words is "twenty-eight billion, seven hundred eight million, six hundred thirty-one thousand, three hundred eighty-eight".