30688381 has 4 divisors (see below), whose sum is σ = 30725212. Its totient is φ = 30651552.

The previous prime is 30688373. The next prime is 30688391. The reversal of 30688381 is 18388603.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18388603 = 113 ⋅162731.

It can be written as a sum of positive squares in 2 ways, for example, as 16475481 + 14212900 = 4059^2 + 3770^2 .

It is a cyclic number.

It is not a de Polignac number, because 30688381 - 2³ = 30688373 is a prime.

It is a super-2 number, since 2×30688381² = 1883553456802322, which contains 22 as substring.

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 30688381.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (30688331) 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, 17136 + ... + 18841.

It is an arithmetic number, because the mean of its divisors is an integer number (7681303).

Almost surely, 2^30688381 is an apocalyptic number.

It is an amenable number.

30688381 is a deficient number, since it is larger than the sum of its proper divisors (36831).

30688381 is an equidigital number, since it uses as much as digits as its factorization.

30688381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36830.

The product of its (nonzero) digits is 27648, while the sum is 37.

The square root of 30688381 is about 5539.7094689162. The cubic root of 30688381 is about 313.0819228446.

It can be divided in two parts, 3068 and 8381, that added together give a square (11449 = 107²).

The spelling of 30688381 in words is "thirty million, six hundred eighty-eight thousand, three hundred eighty-one".