20110309981 has 2 divisors, whose sum is σ = 20110309982. Its totient is φ = 20110309980.

The previous prime is 20110309979. The next prime is 20110310029. The reversal of 20110309981 is 18990301102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12491638756 + 7618671225 = 111766^2 + 87285^2 .

It is a cyclic number.

It is not a de Polignac number, because 20110309981 - 2¹ = 20110309979 is a prime.

It is a super-2 number, since 2×20110309981² (a number of 21 digits) contains 22 as substring.

Together with 20110309979, 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 (20110309781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10055154990 + 10055154991.

It is an arithmetic number, because the mean of its divisors is an integer number (10055154991).

Almost surely, 2^20110309981 is an apocalyptic number.

It is an amenable number.

20110309981 is a deficient number, since it is larger than the sum of its proper divisors (1).

20110309981 is an equidigital number, since it uses as much as digits as its factorization.

20110309981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3888, while the sum is 34.

The spelling of 20110309981 in words is "twenty billion, one hundred ten million, three hundred nine thousand, nine hundred eighty-one".