28312913 has 4 divisors (see below), whose sum is σ = 28374528. Its totient is φ = 28251300.

The previous prime is 28312901. The next prime is 28312943. The reversal of 28312913 is 31921382.

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 28312913 - 2¹⁸ = 28050769 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28312943) 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, 30113 + ... + 31038.

It is an arithmetic number, because the mean of its divisors is an integer number (7093632).

Almost surely, 2^28312913 is an apocalyptic number.

It is an amenable number.

28312913 is a deficient number, since it is larger than the sum of its proper divisors (61615).

28312913 is an equidigital number, since it uses as much as digits as its factorization.

28312913 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61614.

The product of its digits is 2592, while the sum is 29.

The square root of 28312913 is about 5320.9879721721. The cubic root of 28312913 is about 304.7858857358.

The spelling of 28312913 in words is "twenty-eight million, three hundred twelve thousand, nine hundred thirteen".