28012397 has 4 divisors (see below), whose sum is σ = 32014176. Its totient is φ = 24010620.

The previous prime is 28012381. The next prime is 28012409. The reversal of 28012397 is 79321082.

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 28012397 - 2⁴ = 28012381 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 (28012337) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2000879 + ... + 2000892.

It is an arithmetic number, because the mean of its divisors is an integer number (8003544).

Almost surely, 2^28012397 is an apocalyptic number.

It is an amenable number.

28012397 is a deficient number, since it is larger than the sum of its proper divisors (4001779).

28012397 is an equidigital number, since it uses as much as digits as its factorization.

28012397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4001778.

The product of its (nonzero) digits is 6048, while the sum is 32.

The square root of 28012397 is about 5292.6738988908. The cubic root of 28012397 is about 303.7037055675.

The spelling of 28012397 in words is "twenty-eight million, twelve thousand, three hundred ninety-seven".