30685778 has 6 divisors (see below), whose sum is σ = 46040421. Its totient is φ = 15338972.

The previous prime is 30685777. The next prime is 30685793. The reversal of 30685778 is 87758603.

It can be written as a sum of positive squares in 2 ways, for example, as 27384289 + 3301489 = 5233^2 + 1817^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=3917.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (30685777) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 5876 + ... + 9792.

Almost surely, 2^30685778 is an apocalyptic number.

30685778 is a deficient number, since it is larger than the sum of its proper divisors (15354643).

30685778 is an frugal number, since it uses more digits than its factorization.

30685778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7836 (or 3919 counting only the distinct ones).

The product of its (nonzero) digits is 282240, while the sum is 44.

The square root of 30685778 is about 5539.4745238154. The cubic root of 30685778 is about 313.0730706856.

The spelling of 30685778 in words is "thirty million, six hundred eighty-five thousand, seven hundred seventy-eight".