30128561 has 2 divisors, whose sum is σ = 30128562. Its totient is φ = 30128560.

The previous prime is 30128557. The next prime is 30128569. The reversal of 30128561 is 16582103.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21390625 + 8737936 = 4625^2 + 2956^2 .

It is a cyclic number.

It is not a de Polignac number, because 30128561 - 2² = 30128557 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 30128561.

It is not a weakly prime, because it can be changed into another prime (30128569) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15064280 + 15064281.

It is an arithmetic number, because the mean of its divisors is an integer number (15064281).

Almost surely, 2^30128561 is an apocalyptic number.

It is an amenable number.

30128561 is a deficient number, since it is larger than the sum of its proper divisors (1).

30128561 is an equidigital number, since it uses as much as digits as its factorization.

30128561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1440, while the sum is 26.

The square root of 30128561 is about 5488.9489886498. The cubic root of 30128561 is about 311.1664724279.

The spelling of 30128561 in words is "thirty million, one hundred twenty-eight thousand, five hundred sixty-one".