30857128 has 8 divisors (see below), whose sum is σ = 57857130. Its totient is φ = 15428560.

The previous prime is 30857119. The next prime is 30857129. The reversal of 30857128 is 82175803.

It can be written as a sum of positive squares in only one way, i.e., 19554084 + 11303044 = 4422^2 + 3362^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a junction number, because it is equal to n+sod(n) for n = 30857093 and 30857102.

It is not an unprimeable number, because it can be changed into a prime (30857129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1928563 + ... + 1928578.

Almost surely, 2^30857128 is an apocalyptic number.

It is an amenable number.

30857128 is a deficient number, since it is larger than the sum of its proper divisors (27000002).

30857128 is a wasteful number, since it uses less digits than its factorization.

30857128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3857147 (or 3857143 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 34.

The square root of 30857128 is about 5554.9192613394. The cubic root of 30857128 is about 313.6547248052.

The spelling of 30857128 in words is "thirty million, eight hundred fifty-seven thousand, one hundred twenty-eight".