30130021981 has 2 divisors, whose sum is σ = 30130021982. Its totient is φ = 30130021980.

The previous prime is 30130021973. The next prime is 30130022017. The reversal of 30130021981 is 18912003103.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 29973996900 + 156025081 = 173130^2 + 12491^2 .

It is a cyclic number.

It is not a de Polignac number, because 30130021981 - 2³ = 30130021973 is a prime.

It is a super-2 number, since 2×30130021981² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (30130021081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15065010990 + 15065010991.

It is an arithmetic number, because the mean of its divisors is an integer number (15065010991).

Almost surely, 2^30130021981 is an apocalyptic number.

It is an amenable number.

30130021981 is a deficient number, since it is larger than the sum of its proper divisors (1).

30130021981 is an equidigital number, since it uses as much as digits as its factorization.

30130021981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1296, while the sum is 28.

The spelling of 30130021981 in words is "thirty billion, one hundred thirty million, twenty-one thousand, nine hundred eighty-one".