28181989738 has 16 divisors (see below), whose sum is σ = 48321941760. Its totient is φ = 12075505776.

The previous prime is 28181989711. The next prime is 28181989747. The reversal of 28181989738 is 83798918182.

It is a self number, because there is not a number n which added to its sum of digits gives 28181989738.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 136306 + ... + 273757.

It is an arithmetic number, because the mean of its divisors is an integer number (3020121360).

Almost surely, 2^28181989738 is an apocalyptic number.

28181989738 is a deficient number, since it is larger than the sum of its proper divisors (20139952022).

28181989738 is a wasteful number, since it uses less digits than its factorization.

28181989738 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 414981.

The product of its digits is 13934592, while the sum is 64.

The spelling of 28181989738 in words is "twenty-eight billion, one hundred eighty-one million, nine hundred eighty-nine thousand, seven hundred thirty-eight".