28397739 has 4 divisors (see below), whose sum is σ = 37863656. Its totient is φ = 18931824.

The previous prime is 28397717. The next prime is 28397779. The reversal of 28397739 is 93779382.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 28397739 - 2⁹ = 28397227 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28397779) 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, 4732954 + ... + 4732959.

It is an arithmetic number, because the mean of its divisors is an integer number (9465914).

Almost surely, 2^28397739 is an apocalyptic number.

28397739 is a deficient number, since it is larger than the sum of its proper divisors (9465917).

28397739 is an equidigital number, since it uses as much as digits as its factorization.

28397739 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9465916.

The product of its digits is 571536, while the sum is 48.

The square root of 28397739 is about 5328.9528990225. The cubic root of 28397739 is about 305.0899636075.

The spelling of 28397739 in words is "twenty-eight million, three hundred ninety-seven thousand, seven hundred thirty-nine".