30601997981 has 2 divisors, whose sum is σ = 30601997982. Its totient is φ = 30601997980.

The previous prime is 30601997957. The next prime is 30601997989. The reversal of 30601997981 is 18979910603.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 29752800100 + 849197881 = 172490^2 + 29141^2 .

It is an emirp because it is prime and its reverse (18979910603) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-30601997981 is a prime.

It is a super-2 number, since 2×30601997981² (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 (30601997989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15300998990 + 15300998991.

It is an arithmetic number, because the mean of its divisors is an integer number (15300998991).

Almost surely, 2^30601997981 is an apocalyptic number.

It is an amenable number.

30601997981 is a deficient number, since it is larger than the sum of its proper divisors (1).

30601997981 is an equidigital number, since it uses as much as digits as its factorization.

30601997981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 734832, while the sum is 53.

The spelling of 30601997981 in words is "thirty billion, six hundred one million, nine hundred ninety-seven thousand, nine hundred eighty-one".