30728285 has 32 divisors (see below), whose sum is σ = 44040192. Its totient is φ = 20139840.

The previous prime is 30728281. The next prime is 30728293. The reversal of 30728285 is 58282703.

It is a happy number.

It is not a de Polignac number, because 30728285 - 2² = 30728281 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (30728281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 137684 + ... + 137906.

It is an arithmetic number, because the mean of its divisors is an integer number (1376256).

Almost surely, 2^30728285 is an apocalyptic number.

30728285 is a gapful number since it is divisible by the number (35) formed by its first and last digit.

It is an amenable number.

30728285 is a deficient number, since it is larger than the sum of its proper divisors (13311907).

30728285 is a wasteful number, since it uses less digits than its factorization.

30728285 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 393.

The product of its (nonzero) digits is 26880, while the sum is 35.

The square root of 30728285 is about 5543.3099318007. The cubic root of 30728285 is about 313.2175638656.

It can be divided in two parts, 30728 and 285, that added together give a palindrome (31013).

The spelling of 30728285 in words is "thirty million, seven hundred twenty-eight thousand, two hundred eighty-five".