30778640 has 20 divisors (see below), whose sum is σ = 71560524. Its totient is φ = 12311424.

The previous prime is 30778633. The next prime is 30778663. The reversal of 30778640 is 4687703.

It can be written as a sum of positive squares in 2 ways, for example, as 22391824 + 8386816 = 4732^2 + 2896^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a hoax number, since the sum of its digits (35) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 30778640.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 192287 + ... + 192446.

Almost surely, 2^30778640 is an apocalyptic number.

It is an amenable number.

30778640 is an abundant number, since it is smaller than the sum of its proper divisors (40781884).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

30778640 is a wasteful number, since it uses less digits than its factorization.

30778640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 384746 (or 384740 counting only the distinct ones).

The product of its (nonzero) digits is 28224, while the sum is 35.

The square root of 30778640 is about 5547.8500340222. The cubic root of 30778640 is about 313.3885622681.

The spelling of 30778640 in words is "thirty million, seven hundred seventy-eight thousand, six hundred forty".