30138681 has 4 divisors (see below), whose sum is σ = 40184912. Its totient is φ = 20092452.

The previous prime is 30138679. The next prime is 30138701. The reversal of 30138681 is 18683103.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 18683103 = 3 ⋅6227701.

It is not a de Polignac number, because 30138681 - 2¹ = 30138679 is a prime.

It is a super-2 number, since 2×30138681² = 1816680184839522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (30138601) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5023111 + ... + 5023116.

It is an arithmetic number, because the mean of its divisors is an integer number (10046228).

Almost surely, 2^30138681 is an apocalyptic number.

It is an amenable number.

30138681 is a deficient number, since it is larger than the sum of its proper divisors (10046231).

30138681 is a wasteful number, since it uses less digits than its factorization.

30138681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10046230.

The product of its (nonzero) digits is 3456, while the sum is 30.

The square root of 30138681 is about 5489.8707635062. The cubic root of 30138681 is about 311.2013081683.

The spelling of 30138681 in words is "thirty million, one hundred thirty-eight thousand, six hundred eighty-one".