28400117 has 4 divisors (see below), whose sum is σ = 29894880. Its totient is φ = 26905356.

The previous prime is 28400107. The next prime is 28400129. The reversal of 28400117 is 71100482.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 28400117 - 2¹⁰ = 28399093 is a prime.

It is a super-2 number, since 2×28400117² = 1613133291227378, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28400092 and 28400101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28400107) 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, 747353 + ... + 747390.

It is an arithmetic number, because the mean of its divisors is an integer number (7473720).

Almost surely, 2^28400117 is an apocalyptic number.

It is an amenable number.

28400117 is a deficient number, since it is larger than the sum of its proper divisors (1494763).

28400117 is a wasteful number, since it uses less digits than its factorization.

28400117 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1494762.

The product of its (nonzero) digits is 448, while the sum is 23.

The square root of 28400117 is about 5329.1760151078. The cubic root of 28400117 is about 305.0984793522.

Adding to 28400117 its reverse (71100482), we get a palindrome (99500599).

The spelling of 28400117 in words is "twenty-eight million, four hundred thousand, one hundred seventeen".