30921827813 has 2 divisors, whose sum is σ = 30921827814. Its totient is φ = 30921827812.

The previous prime is 30921827803. The next prime is 30921827879. The reversal of 30921827813 is 31872812903.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 29315261089 + 1606566724 = 171217^2 + 40082^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-30921827813 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (30921827803) 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, 15460913906 + 15460913907.

It is an arithmetic number, because the mean of its divisors is an integer number (15460913907).

Almost surely, 2^30921827813 is an apocalyptic number.

It is an amenable number.

30921827813 is a deficient number, since it is larger than the sum of its proper divisors (1).

30921827813 is an equidigital number, since it uses as much as digits as its factorization.

30921827813 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 145152, while the sum is 44.

The spelling of 30921827813 in words is "thirty billion, nine hundred twenty-one million, eight hundred twenty-seven thousand, eight hundred thirteen".