30128929 has 4 divisors (see below), whose sum is σ = 30147460. Its totient is φ = 30110400.

The previous prime is 30128893. The next prime is 30128933. The reversal of 30128929 is 92982103.

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 11189025 + 18939904 = 3345^2 + 4352^2 .

It is a cyclic number.

It is not a de Polignac number, because 30128929 - 2⁷ = 30128801 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 30128894 and 30128903.

It is not an unprimeable number, because it can be changed into a prime (30128429) 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, 6564 + ... + 10165.

It is an arithmetic number, because the mean of its divisors is an integer number (7536865).

Almost surely, 2^30128929 is an apocalyptic number.

It is an amenable number.

30128929 is a deficient number, since it is larger than the sum of its proper divisors (18531).

30128929 is a wasteful number, since it uses less digits than its factorization.

30128929 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18530.

The product of its (nonzero) digits is 7776, while the sum is 34.

The square root of 30128929 is about 5488.9825104476. The cubic root of 30128929 is about 311.1677393187.

The spelling of 30128929 in words is "thirty million, one hundred twenty-eight thousand, nine hundred twenty-nine".