30139281 has 6 divisors (see below), whose sum is σ = 43534530. Its totient is φ = 20092848.

The previous prime is 30139279. The next prime is 30139297. The reversal of 30139281 is 18293103.

It can be written as a sum of positive squares in only one way, i.e., 30074256 + 65025 = 5484^2 + 255^2 .

It is not a de Polignac number, because 30139281 - 2¹ = 30139279 is a prime.

It is a super-2 number, since 2×30139281² = 1816752518393922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (30139261) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1674396 + ... + 1674413.

It is an arithmetic number, because the mean of its divisors is an integer number (7255755).

Almost surely, 2^30139281 is an apocalyptic number.

It is an amenable number.

30139281 is a deficient number, since it is larger than the sum of its proper divisors (13395249).

30139281 is a wasteful number, since it uses less digits than its factorization.

30139281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3348815 (or 3348812 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 30139281 is about 5489.9254093293. The cubic root of 30139281 is about 311.2033732835.

The spelling of 30139281 in words is "thirty million, one hundred thirty-nine thousand, two hundred eighty-one".