28431791 has 2 divisors, whose sum is σ = 28431792. Its totient is φ = 28431790.

The previous prime is 28431779. The next prime is 28431829. The reversal of 28431791 is 19713482.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28431791 is a prime.

It is a Chen prime.

It is equal to p_1766609 and since 28431791 and 1766609 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28431731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14215895 + 14215896.

It is an arithmetic number, because the mean of its divisors is an integer number (14215896).

Almost surely, 2^28431791 is an apocalyptic number.

28431791 is a deficient number, since it is larger than the sum of its proper divisors (1).

28431791 is an equidigital number, since it uses as much as digits as its factorization.

28431791 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12096, while the sum is 35.

The square root of 28431791 is about 5332.1469409610. The cubic root of 28431791 is about 305.2118603275.

The spelling of 28431791 in words is "twenty-eight million, four hundred thirty-one thousand, seven hundred ninety-one".