30021031981 has 2 divisors, whose sum is σ = 30021031982. Its totient is φ = 30021031980.

The previous prime is 30021031961. The next prime is 30021031987. The reversal of 30021031981 is 18913012003.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 30010365225 + 10666756 = 173235^2 + 3266^2 .

It is a cyclic number.

It is not a de Polignac number, because 30021031981 - 2¹⁷ = 30020900909 is a prime.

It is a super-2 number, since 2×30021031981² (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 (30021031987) 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, 15010515990 + 15010515991.

It is an arithmetic number, because the mean of its divisors is an integer number (15010515991).

Almost surely, 2^30021031981 is an apocalyptic number.

It is an amenable number.

30021031981 is a deficient number, since it is larger than the sum of its proper divisors (1).

30021031981 is an equidigital number, since it uses as much as digits as its factorization.

30021031981 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.

Adding to 30021031981 its reverse (18913012003), we get a palindrome (48934043984).

The spelling of 30021031981 in words is "thirty billion, twenty-one million, thirty-one thousand, nine hundred eighty-one".