28517431 has 2 divisors, whose sum is σ = 28517432. Its totient is φ = 28517430.

The previous prime is 28517429. The next prime is 28517443. The reversal of 28517431 is 13471582.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 28517431 - 2¹ = 28517429 is a prime.

It is a super-2 number, since 2×28517431² = 1626487741679522, which contains 22 as substring.

Together with 28517429, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 28517393 and 28517402.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28512431) 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 as a sum of consecutive naturals, namely, 14258715 + 14258716.

It is an arithmetic number, because the mean of its divisors is an integer number (14258716).

Almost surely, 2^28517431 is an apocalyptic number.

28517431 is a deficient number, since it is larger than the sum of its proper divisors (1).

28517431 is an equidigital number, since it uses as much as digits as its factorization.

28517431 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6720, while the sum is 31.

The square root of 28517431 is about 5340.1714391956. The cubic root of 28517431 is about 305.5179981950.

The spelling of 28517431 in words is "twenty-eight million, five hundred seventeen thousand, four hundred thirty-one".