28647631 has 2 divisors, whose sum is σ = 28647632. Its totient is φ = 28647630.

The previous prime is 28647629. The next prime is 28647637. The reversal of 28647631 is 13674682.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 28647631 - 2¹ = 28647629 is a prime.

It is a super-3 number, since 3×28647631³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

Together with 28647629, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28647637) 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, 14323815 + 14323816.

It is an arithmetic number, because the mean of its divisors is an integer number (14323816).

Almost surely, 2^28647631 is an apocalyptic number.

28647631 is a deficient number, since it is larger than the sum of its proper divisors (1).

28647631 is an equidigital number, since it uses as much as digits as its factorization.

28647631 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 48384, while the sum is 37.

The square root of 28647631 is about 5352.3481762681. The cubic root of 28647631 is about 305.9822529471.

The spelling of 28647631 in words is "twenty-eight million, six hundred forty-seven thousand, six hundred thirty-one".