28949993 has 4 divisors (see below), whose sum is σ = 29117508. Its totient is φ = 28782480.

The previous prime is 28949971. The next prime is 28950007. The reversal of 28949993 is 39994982.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 17572864 + 11377129 = 4192^2 + 3373^2 .

It is a cyclic number.

It is not a de Polignac number, because 28949993 - 2⁸ = 28949737 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28949953) 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 3 ways as a sum of consecutive naturals, for example, 83498 + ... + 83843.

It is an arithmetic number, because the mean of its divisors is an integer number (7279377).

Almost surely, 2^28949993 is an apocalyptic number.

It is an amenable number.

28949993 is a deficient number, since it is larger than the sum of its proper divisors (167515).

28949993 is a wasteful number, since it uses less digits than its factorization.

28949993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 167514.

The product of its digits is 1259712, while the sum is 53.

The square root of 28949993 is about 5380.5197704311. The cubic root of 28949993 is about 307.0549863135.

The spelling of 28949993 in words is "twenty-eight million, nine hundred forty-nine thousand, nine hundred ninety-three".