28109497 has 8 divisors (see below), whose sum is σ = 31316040. Its totient is φ = 25052160.

The previous prime is 28109491. The next prime is 28109503. The reversal of 28109497 is 79490182.

It is an interprime number because it is at equal distance from previous prime (28109491) and next prime (28109503).

It can be written as a sum of positive squares in 4 ways, for example, as 1679616 + 26429881 = 1296^2 + 5141^2 .

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 28109497 - 2³ = 28109489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28109491) 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, 36904 + ... + 37657.

It is an arithmetic number, because the mean of its divisors is an integer number (3914505).

Almost surely, 2^28109497 is an apocalyptic number.

It is an amenable number.

28109497 is a deficient number, since it is larger than the sum of its proper divisors (3206543).

28109497 is a wasteful number, since it uses less digits than its factorization.

28109497 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74603.

The product of its (nonzero) digits is 36288, while the sum is 40.

The square root of 28109497 is about 5301.8390205664. The cubic root of 28109497 is about 304.0542125443.

The spelling of 28109497 in words is "twenty-eight million, one hundred nine thousand, four hundred ninety-seven".