28081844661 has 16 divisors (see below), whose sum is σ = 40337252480. Its totient is φ = 17274876480.

The previous prime is 28081844647. The next prime is 28081844663. The reversal of 28081844661 is 16644818082.

It is a happy number.

It is not a de Polignac number, because 28081844661 - 2⁵ = 28081844629 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28081844661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28081844663) 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, 20146 + ... + 237843.

It is an arithmetic number, because the mean of its divisors is an integer number (2521078280).

Almost surely, 2^28081844661 is an apocalyptic number.

It is an amenable number.

28081844661 is a deficient number, since it is larger than the sum of its proper divisors (12255407819).

28081844661 is a wasteful number, since it uses less digits than its factorization.

28081844661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 260796.

The product of its (nonzero) digits is 589824, while the sum is 48.

The spelling of 28081844661 in words is "twenty-eight billion, eighty-one million, eight hundred forty-four thousand, six hundred sixty-one".