28019913 has 4 divisors (see below), whose sum is σ = 37359888. Its totient is φ = 18679940.

The previous prime is 28019899. The next prime is 28019917. The reversal of 28019913 is 31991082.

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 28019913 - 2⁹ = 28019401 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28019917) 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, 4669983 + ... + 4669988.

It is an arithmetic number, because the mean of its divisors is an integer number (9339972).

Almost surely, 2^28019913 is an apocalyptic number.

It is an amenable number.

28019913 is a deficient number, since it is larger than the sum of its proper divisors (9339975).

28019913 is an equidigital number, since it uses as much as digits as its factorization.

28019913 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9339974.

The product of its (nonzero) digits is 3888, while the sum is 33.

The square root of 28019913 is about 5293.3838893472. The cubic root of 28019913 is about 303.7308653631.

The spelling of 28019913 in words is "twenty-eight million, nineteen thousand, nine hundred thirteen".