28081001 has 8 divisors (see below), whose sum is σ = 30322824. Its totient is φ = 25850880.

The previous prime is 28080979. The next prime is 28081007. The reversal of 28081001 is 10018082.

It can be written as a sum of positive squares in 4 ways, for example, as 4305625 + 23775376 = 2075^2 + 4876^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 28081001 - 2¹⁰ = 28079977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28081007) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2441 + ... + 7881.

It is an arithmetic number, because the mean of its divisors is an integer number (3790353).

Almost surely, 2^28081001 is an apocalyptic number.

It is an amenable number.

28081001 is a deficient number, since it is larger than the sum of its proper divisors (2241823).

28081001 is a wasteful number, since it uses less digits than its factorization.

28081001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5851.

The product of its (nonzero) digits is 128, while the sum is 20.

The square root of 28081001 is about 5299.1509697309. The cubic root of 28081001 is about 303.9514328288.

Adding to 28081001 its reverse (10018082), we get a palindrome (38099083).

The spelling of 28081001 in words is "twenty-eight million, eighty-one thousand, one".