30028391 has 4 divisors (see below), whose sum is σ = 30048792. Its totient is φ = 30007992.

The previous prime is 30028357. The next prime is 30028399. The reversal of 30028391 is 19382003.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19382003 = 199 ⋅97397.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-30028391 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 30028391.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (30028399) 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 3 ways as a sum of consecutive naturals, for example, 7805 + ... + 10998.

It is an arithmetic number, because the mean of its divisors is an integer number (7512198).

Almost surely, 2^30028391 is an apocalyptic number.

30028391 is a deficient number, since it is larger than the sum of its proper divisors (20401).

30028391 is a wasteful number, since it uses less digits than its factorization.

30028391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20400.

The product of its (nonzero) digits is 1296, while the sum is 26.

The square root of 30028391 is about 5479.8166940145. The cubic root of 30028391 is about 310.8212390665.

The spelling of 30028391 in words is "thirty million, twenty-eight thousand, three hundred ninety-one".