28196309 has 4 divisors (see below), whose sum is σ = 28411680. Its totient is φ = 27980940.

The previous prime is 28196303. The next prime is 28196327. The reversal of 28196309 is 90369182.

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 28196309 - 2⁴ = 28196293 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28196303) 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, 107489 + ... + 107750.

It is an arithmetic number, because the mean of its divisors is an integer number (7102920).

Almost surely, 2^28196309 is an apocalyptic number.

It is an amenable number.

28196309 is a deficient number, since it is larger than the sum of its proper divisors (215371).

28196309 is a wasteful number, since it uses less digits than its factorization.

28196309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 215370.

The product of its (nonzero) digits is 23328, while the sum is 38.

The square root of 28196309 is about 5310.0196798129. The cubic root of 28196309 is about 304.3668996041.

The spelling of 28196309 in words is "twenty-eight million, one hundred ninety-six thousand, three hundred nine".