28015649 has 4 divisors (see below), whose sum is σ = 28073664. Its totient is φ = 27957636.

The previous prime is 28015627. The next prime is 28015651. The reversal of 28015649 is 94651082.

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 a de Polignac number, because none of the positive numbers 2^k-28015649 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28015349) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28277 + ... + 29250.

It is an arithmetic number, because the mean of its divisors is an integer number (7018416).

Almost surely, 2^28015649 is an apocalyptic number.

It is an amenable number.

28015649 is a deficient number, since it is larger than the sum of its proper divisors (58015).

28015649 is an equidigital number, since it uses as much as digits as its factorization.

28015649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58014.

The product of its (nonzero) digits is 17280, while the sum is 35.

The square root of 28015649 is about 5292.9811070889. The cubic root of 28015649 is about 303.7154575814.

The spelling of 28015649 in words is "twenty-eight million, fifteen thousand, six hundred forty-nine".