28204397 has 16 divisors (see below), whose sum is σ = 31460352. Its totient is φ = 25116480.

The previous prime is 28204391. The next prime is 28204409. The reversal of 28204397 is 79340282.

It is a cyclic number.

It is not a de Polignac number, because 28204397 - 2⁶ = 28204333 is a prime.

It is a Smith number, since the sum of its digits (35) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28204391) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 91718 + ... + 92024.

It is an arithmetic number, because the mean of its divisors is an integer number (1966272).

Almost surely, 2^28204397 is an apocalyptic number.

It is an amenable number.

28204397 is a deficient number, since it is larger than the sum of its proper divisors (3255955).

28204397 is a wasteful number, since it uses less digits than its factorization.

28204397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 548.

The product of its (nonzero) digits is 24192, while the sum is 35.

The square root of 28204397 is about 5310.7812043051. The cubic root of 28204397 is about 304.3959989701.

The spelling of 28204397 in words is "twenty-eight million, two hundred four thousand, three hundred ninety-seven".