30688993 has 4 divisors (see below), whose sum is σ = 30700948. Its totient is φ = 30677040.

The previous prime is 30688967. The next prime is 30688997. The reversal of 30688993 is 39988603.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 39988603 = 5521 ⋅7243.

It can be written as a sum of positive squares in 2 ways, for example, as 23892544 + 6796449 = 4888^2 + 2607^2 .

It is a cyclic number.

It is not a de Polignac number, because 30688993 - 2¹⁷ = 30557921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (30688997) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 378 + ... + 7843.

It is an arithmetic number, because the mean of its divisors is an integer number (7675237).

Almost surely, 2^30688993 is an apocalyptic number.

It is an amenable number.

30688993 is a deficient number, since it is larger than the sum of its proper divisors (11955).

30688993 is an equidigital number, since it uses as much as digits as its factorization.

30688993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11954.

The product of its (nonzero) digits is 279936, while the sum is 46.

The square root of 30688993 is about 5539.7647061947. The cubic root of 30688993 is about 313.0840040325.

The spelling of 30688993 in words is "thirty million, six hundred eighty-eight thousand, nine hundred ninety-three".