28208660121890 has 8 divisors (see below), whose sum is σ = 50775588219420. Its totient is φ = 11283464048752.

The previous prime is 28208660121881. The next prime is 28208660121931. The reversal of 28208660121890 is 9812106680282.

It can be written as a sum of positive squares in 2 ways, for example, as 27012561364321 + 1196098757569 = 5197361^2 + 1093663^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1410433006085 + ... + 1410433006104.

Almost surely, 2^{28208660121890} is an apocalyptic number.

28208660121890 is a deficient number, since it is larger than the sum of its proper divisors (22566928097530).

28208660121890 is a wasteful number, since it uses less digits than its factorization.

28208660121890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2820866012196.

The product of its (nonzero) digits is 1327104, while the sum is 53.

The spelling of 28208660121890 in words is "twenty-eight trillion, two hundred eight billion, six hundred sixty million, one hundred twenty-one thousand, eight hundred ninety".