30311121991 has 2 divisors, whose sum is σ = 30311121992. Its totient is φ = 30311121990.

The previous prime is 30311121989. The next prime is 30311122087. The reversal of 30311121991 is 19912111303.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 30311121991 - 2¹ = 30311121989 is a prime.

Together with 30311121989, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (30311121961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15155560995 + 15155560996.

It is an arithmetic number, because the mean of its divisors is an integer number (15155560996).

Almost surely, 2^30311121991 is an apocalyptic number.

30311121991 is a deficient number, since it is larger than the sum of its proper divisors (1).

30311121991 is an equidigital number, since it uses as much as digits as its factorization.

30311121991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1458, while the sum is 31.

The spelling of 30311121991 in words is "thirty billion, three hundred eleven million, one hundred twenty-one thousand, nine hundred ninety-one".