28393993 has 2 divisors, whose sum is σ = 28393994. Its totient is φ = 28393992.

The previous prime is 28393973. The next prime is 28394027. The reversal of 28393993 is 39939382.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 22401289 + 5992704 = 4733^2 + 2448^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28393993 is a prime.

It is not a weakly prime, because it can be changed into another prime (28393903) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14196996 + 14196997.

It is an arithmetic number, because the mean of its divisors is an integer number (14196997).

Almost surely, 2^28393993 is an apocalyptic number.

It is an amenable number.

28393993 is a deficient number, since it is larger than the sum of its proper divisors (1).

28393993 is an equidigital number, since it uses as much as digits as its factorization.

28393993 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 314928, while the sum is 46.

The square root of 28393993 is about 5328.6014112523. The cubic root of 28393993 is about 305.0765480176.

The spelling of 28393993 in words is "twenty-eight million, three hundred ninety-three thousand, nine hundred ninety-three".