30728525 has 6 divisors (see below), whose sum is σ = 38103402. Its totient is φ = 24582800.

The previous prime is 30728521. The next prime is 30728527. The reversal of 30728525 is 52582703.

It can be written as a sum of positive squares in 3 ways, for example, as 1590121 + 29138404 = 1261^2 + 5398^2 .

It is not a de Polignac number, because 30728525 - 2² = 30728521 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 30728491 and 30728500.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (30728521) 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 5 ways as a sum of consecutive naturals, for example, 614546 + ... + 614595.

It is an arithmetic number, because the mean of its divisors is an integer number (6350567).

Almost surely, 2^30728525 is an apocalyptic number.

It is an amenable number.

30728525 is a deficient number, since it is larger than the sum of its proper divisors (7374877).

30728525 is a wasteful number, since it uses less digits than its factorization.

30728525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1229151 (or 1229146 counting only the distinct ones).

The product of its (nonzero) digits is 16800, while the sum is 32.

The square root of 30728525 is about 5543.3315794746. The cubic root of 30728525 is about 313.2183793143.

The spelling of 30728525 in words is "thirty million, seven hundred twenty-eight thousand, five hundred twenty-five".