30728778 has 8 divisors (see below), whose sum is σ = 61457568. Its totient is φ = 10242924.

The previous prime is 30728771. The next prime is 30728821. The reversal of 30728778 is 87782703.

It is a sphenic number, since it is the product of 3 distinct primes.

30728778 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (30728771) 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, 2560726 + ... + 2560737.

It is an arithmetic number, because the mean of its divisors is an integer number (7682196).

Almost surely, 2^30728778 is an apocalyptic number.

30728778 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

30728778 is a wasteful number, since it uses less digits than its factorization.

30728778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5121468.

The product of its (nonzero) digits is 131712, while the sum is 42.

The square root of 30728778 is about 5543.3543996393. The cubic root of 30728778 is about 313.2192389285.

The spelling of 30728778 in words is "thirty million, seven hundred twenty-eight thousand, seven hundred seventy-eight".