28281122661 has 16 divisors (see below), whose sum is σ = 42092835840. Its totient is φ = 16741467120.

The previous prime is 28281122657. The next prime is 28281122671. The reversal of 28281122661 is 16622118282.

It is a happy number.

It is not a de Polignac number, because 28281122661 - 2² = 28281122657 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28281122671) 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, 9963741 + ... + 9966578.

It is an arithmetic number, because the mean of its divisors is an integer number (2630802240).

Almost surely, 2^28281122661 is an apocalyptic number.

It is an amenable number.

28281122661 is a deficient number, since it is larger than the sum of its proper divisors (13811713179).

28281122661 is a wasteful number, since it uses less digits than its factorization.

28281122661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19930376.

The product of its digits is 36864, while the sum is 39.

The spelling of 28281122661 in words is "twenty-eight billion, two hundred eighty-one million, one hundred twenty-two thousand, six hundred sixty-one".