28978156388 has 12 divisors (see below), whose sum is σ = 52460455740. Its totient is φ = 13989454752.

The previous prime is 28978156381. The next prime is 28978156411. The reversal of 28978156388 is 88365187982.

It can be written as a sum of positive squares in 2 ways, for example, as 22131917824 + 6846238564 = 148768^2 + 82742^2 .

It is not an unprimeable number, because it can be changed into a prime (28978156381) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 124905731 + ... + 124905962.

It is an arithmetic number, because the mean of its divisors is an integer number (4371704645).

Almost surely, 2^28978156388 is an apocalyptic number.

It is an amenable number.

28978156388 is a deficient number, since it is larger than the sum of its proper divisors (23482299352).

28978156388 is a wasteful number, since it uses less digits than its factorization.

28978156388 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 249811726 (or 249811724 counting only the distinct ones).

The product of its digits is 46448640, while the sum is 65.

The spelling of 28978156388 in words is "twenty-eight billion, nine hundred seventy-eight million, one hundred fifty-six thousand, three hundred eighty-eight".