28431305 has 16 divisors (see below), whose sum is σ = 39204864. Its totient is φ = 19389120.

The previous prime is 28431269. The next prime is 28431313. The reversal of 28431305 is 50313482.

It is not a de Polignac number, because 28431305 - 2²² = 24237001 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4559 + ... + 8811.

It is an arithmetic number, because the mean of its divisors is an integer number (2450304).

Almost surely, 2^28431305 is an apocalyptic number.

It is an amenable number.

28431305 is a deficient number, since it is larger than the sum of its proper divisors (10773559).

28431305 is a wasteful number, since it uses less digits than its factorization.

28431305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4456.

The product of its (nonzero) digits is 2880, while the sum is 26.

The square root of 28431305 is about 5332.1013681287. The cubic root of 28431305 is about 305.2101212671.

Adding to 28431305 its reverse (50313482), we get a palindrome (78744787).

The spelling of 28431305 in words is "twenty-eight million, four hundred thirty-one thousand, three hundred five".