30398721 has 16 divisors (see below), whose sum is σ = 42071040. Its totient is φ = 19509840.

The previous prime is 30398717. The next prime is 30398723. The reversal of 30398721 is 12789303.

It is not a de Polignac number, because 30398721 - 2² = 30398717 is a prime.

It is not an unprimeable number, because it can be changed into a prime (30398723) 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 15 ways as a sum of consecutive naturals, for example, 7500 + ... + 10818.

It is an arithmetic number, because the mean of its divisors is an integer number (2629440).

Almost surely, 2^30398721 is an apocalyptic number.

It is an amenable number.

30398721 is a deficient number, since it is larger than the sum of its proper divisors (11672319).

30398721 is a wasteful number, since it uses less digits than its factorization.

30398721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3436.

The product of its (nonzero) digits is 9072, while the sum is 33.

The square root of 30398721 is about 5513.5035141006. The cubic root of 30398721 is about 312.0937731774.

The spelling of 30398721 in words is "thirty million, three hundred ninety-eight thousand, seven hundred twenty-one".