30128513 has 4 divisors (see below), whose sum is σ = 30141780. Its totient is φ = 30115248.

The previous prime is 30128503. The next prime is 30128519. The reversal of 30128513 is 31582103.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 21086464 + 9042049 = 4592^2 + 3007^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-30128513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (30128519) 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 3 ways as a sum of consecutive naturals, for example, 2270 + ... + 8087.

It is an arithmetic number, because the mean of its divisors is an integer number (7535445).

Almost surely, 2^30128513 is an apocalyptic number.

It is an amenable number.

30128513 is a deficient number, since it is larger than the sum of its proper divisors (13267).

30128513 is a wasteful number, since it uses less digits than its factorization.

30128513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13266.

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 30128513 is about 5488.9446162263. The cubic root of 30128513 is about 311.1663071805.

The spelling of 30128513 in words is "thirty million, one hundred twenty-eight thousand, five hundred thirteen".