28687031 has 2 divisors, whose sum is σ = 28687032. Its totient is φ = 28687030.

The previous prime is 28687013. The next prime is 28687051. The reversal of 28687031 is 13078682.

Together with previous prime (28687013) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28687031 is a prime.

It is a super-2 number, since 2×28687031² = 1645891495189922, which contains 22 as substring.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 28686982 and 28687000.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28687051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14343515 + 14343516.

It is an arithmetic number, because the mean of its divisors is an integer number (14343516).

Almost surely, 2^28687031 is an apocalyptic number.

28687031 is a deficient number, since it is larger than the sum of its proper divisors (1).

28687031 is an equidigital number, since it uses as much as digits as its factorization.

28687031 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16128, while the sum is 35.

The square root of 28687031 is about 5356.0275391376. The cubic root of 28687031 is about 306.1224644027.

The spelling of 28687031 in words is "twenty-eight million, six hundred eighty-seven thousand, thirty-one".