30491728 has 10 divisors (see below), whose sum is σ = 59077754. Its totient is φ = 15245856.

The previous prime is 30491719. The next prime is 30491743. The reversal of 30491728 is 82719403.

It can be written as a sum of positive squares in only one way, i.e., 30338064 + 153664 = 5508^2 + 392^2 .

It is a junction number, because it is equal to n+sod(n) for n = 30491693 and 30491702.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 952851 + ... + 952882.

Almost surely, 2^30491728 is an apocalyptic number.

It is an amenable number.

30491728 is a deficient number, since it is larger than the sum of its proper divisors (28586026).

30491728 is a wasteful number, since it uses less digits than its factorization.

30491728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1905741 (or 1905735 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 34.

The square root of 30491728 is about 5521.9315461168. The cubic root of 30491728 is about 312.4117399816.

The spelling of 30491728 in words is "thirty million, four hundred ninety-one thousand, seven hundred twenty-eight".