28208208138 has 32 divisors (see below), whose sum is σ = 63530514432. Its totient is φ = 8272201200.

The previous prime is 28208208097. The next prime is 28208208139. The reversal of 28208208138 is 83180280282.

It is a self number, because there is not a number n which added to its sum of digits gives 28208208138.

It is not an unprimeable number, because it can be changed into a prime (28208208139) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6891456 + ... + 6895547.

It is an arithmetic number, because the mean of its divisors is an integer number (1985328576).

Almost surely, 2^28208208138 is an apocalyptic number.

28208208138 is an abundant number, since it is smaller than the sum of its proper divisors (35322306294).

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

28208208138 is a wasteful number, since it uses less digits than its factorization.

28208208138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13787050.

The product of its (nonzero) digits is 98304, while the sum is 42.

The spelling of 28208208138 in words is "twenty-eight billion, two hundred eight million, two hundred eight thousand, one hundred thirty-eight".