30428857 has 2 divisors, whose sum is σ = 30428858. Its totient is φ = 30428856.

The previous prime is 30428843. The next prime is 30428869. The reversal of 30428857 is 75882403.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 30426256 + 2601 = 5516^2 + 51^2 .

It is an emirp because it is prime and its reverse (75882403) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 30428857 - 2⁷ = 30428729 is a prime.

It is not a weakly prime, because it can be changed into another prime (30428807) 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 as a sum of consecutive naturals, namely, 15214428 + 15214429.

It is an arithmetic number, because the mean of its divisors is an integer number (15214429).

Almost surely, 2^30428857 is an apocalyptic number.

It is an amenable number.

30428857 is a deficient number, since it is larger than the sum of its proper divisors (1).

30428857 is an equidigital number, since it uses as much as digits as its factorization.

30428857 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 53760, while the sum is 37.

The square root of 30428857 is about 5516.2357636345. The cubic root of 30428857 is about 312.1968712833.

It can be divided in two parts, 304 and 28857, that added together give a triangular number (29161 = T₂₄₁).

The spelling of 30428857 in words is "thirty million, four hundred twenty-eight thousand, eight hundred fifty-seven".