30881681 has 2 divisors, whose sum is σ = 30881682. Its totient is φ = 30881680.

The previous prime is 30881629. The next prime is 30881713. The reversal of 30881681 is 18618803.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19219456 + 11662225 = 4384^2 + 3415^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-30881681 is a prime.

It is a super-2 number, since 2×30881681² = 1907356442771522, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (30881621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15440840 + 15440841.

It is an arithmetic number, because the mean of its divisors is an integer number (15440841).

Almost surely, 2^30881681 is an apocalyptic number.

It is an amenable number.

30881681 is a deficient number, since it is larger than the sum of its proper divisors (1).

30881681 is an equidigital number, since it uses as much as digits as its factorization.

30881681 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9216, while the sum is 35.

The square root of 30881681 is about 5557.1288450062. The cubic root of 30881681 is about 313.7378943812.

The spelling of 30881681 in words is "thirty million, eight hundred eighty-one thousand, six hundred eighty-one".