1011101981 has 2 divisors, whose sum is σ = 1011101982. Its totient is φ = 1011101980.

The previous prime is 1011101977. The next prime is 1011102089. The reversal of 1011101981 is 1891011101.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 630461881 + 380640100 = 25109^2 + 19510^2 .

It is a cyclic number.

It is not a de Polignac number, because 1011101981 - 2² = 1011101977 is a prime.

It is a super-2 number, since 2×1011101981² = 2044654431964248722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1011101951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 505550990 + 505550991.

It is an arithmetic number, because the mean of its divisors is an integer number (505550991).

Almost surely, 2^1011101981 is an apocalyptic number.

It is an amenable number.

1011101981 is a deficient number, since it is larger than the sum of its proper divisors (1).

1011101981 is an equidigital number, since it uses as much as digits as its factorization.

1011101981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72, while the sum is 23.

The square root of 1011101981 is about 31797.8298158852. The cubic root of 1011101981 is about 1003.6870492932.

The spelling of 1011101981 in words is "one billion, eleven million, one hundred one thousand, nine hundred eighty-one".