28671643 has 16 divisors (see below), whose sum is σ = 38497536. Its totient is φ = 20622240.

The previous prime is 28671637. The next prime is 28671653. The reversal of 28671643 is 34617682.

It is a cyclic number.

It is not a de Polignac number, because 28671643 - 2⁵ = 28671611 is a prime.

It is a super-2 number, since 2×28671643² = 1644126224638898, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28671653) 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 in 15 ways as a sum of consecutive naturals, for example, 13321 + ... + 15322.

It is an arithmetic number, because the mean of its divisors is an integer number (2406096).

Almost surely, 2^28671643 is an apocalyptic number.

28671643 is a deficient number, since it is larger than the sum of its proper divisors (9825893).

28671643 is a wasteful number, since it uses less digits than its factorization.

28671643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28674.

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

The square root of 28671643 is about 5354.5908340414. The cubic root of 28671643 is about 306.0677189324.

The spelling of 28671643 in words is "twenty-eight million, six hundred seventy-one thousand, six hundred forty-three".