28249643 has 2 divisors, whose sum is σ = 28249644. Its totient is φ = 28249642.

The previous prime is 28249621. The next prime is 28249657. The reversal of 28249643 is 34694282.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 28249643 - 2¹⁸ = 27987499 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 28249597 and 28249606.

It is not a weakly prime, because it can be changed into another prime (28249843) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14124821 + 14124822.

It is an arithmetic number, because the mean of its divisors is an integer number (14124822).

Almost surely, 2^28249643 is an apocalyptic number.

28249643 is a deficient number, since it is larger than the sum of its proper divisors (1).

28249643 is an equidigital number, since it uses as much as digits as its factorization.

28249643 is an evil number, because the sum of its binary digits is even.

The product of its digits is 82944, while the sum is 38.

The square root of 28249643 is about 5315.0393225262. The cubic root of 28249643 is about 304.5586845154.

The spelling of 28249643 in words is "twenty-eight million, two hundred forty-nine thousand, six hundred forty-three".