28100001 has 8 divisors (see below), whose sum is σ = 38026144. Its totient is φ = 18453600.

The previous prime is 28099999. The next prime is 28100011. The reversal of 28100001 is 10000182.

It is a happy number.

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

It is not a de Polignac number, because 28100001 - 2¹ = 28099999 is a prime.

It is a super-2 number, since 2×28100001² = 1579220112400002, which contains 22 as substring.

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 28100001.

It is not an unprimeable number, because it can be changed into a prime (28100011) 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, 69700 + ... + 70101.

It is an arithmetic number, because the mean of its divisors is an integer number (4753268).

Almost surely, 2^28100001 is an apocalyptic number.

It is an amenable number.

28100001 is a deficient number, since it is larger than the sum of its proper divisors (9926143).

28100001 is a wasteful number, since it uses less digits than its factorization.

28100001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 139871.

The product of its (nonzero) digits is 16, while the sum is 12.

The square root of 28100001 is about 5300.9434066023. The cubic root of 28100001 is about 304.0199699774.

Adding to 28100001 its reverse (10000182), we get a palindrome (38100183).

The spelling of 28100001 in words is "twenty-eight million, one hundred thousand, one".