28008401 has 4 divisors (see below), whose sum is σ = 29655972. Its totient is φ = 26360832.

The previous prime is 28008397. The next prime is 28008443. The reversal of 28008401 is 10480082.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 19891600 + 8116801 = 4460^2 + 2849^2 .

It is a cyclic number.

It is not a de Polignac number, because 28008401 - 2² = 28008397 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (28008601) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 823760 + ... + 823793.

It is an arithmetic number, because the mean of its divisors is an integer number (7413993).

Almost surely, 2^28008401 is an apocalyptic number.

It is an amenable number.

28008401 is a deficient number, since it is larger than the sum of its proper divisors (1647571).

28008401 is a wasteful number, since it uses less digits than its factorization.

28008401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1647570.

The product of its (nonzero) digits is 512, while the sum is 23.

The square root of 28008401 is about 5292.2963824790. The cubic root of 28008401 is about 303.6892636555.

Adding to 28008401 its reverse (10480082), we get a palindrome (38488483).

The spelling of 28008401 in words is "twenty-eight million, eight thousand, four hundred one".