100661081 has 2 divisors, whose sum is σ = 100661082. Its totient is φ = 100661080.

The previous prime is 100661051. The next prime is 100661083. The reversal of 100661081 is 180166001.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 90421081 + 10240000 = 9509^2 + 3200^2 .

It is a cyclic number.

It is not a de Polignac number, because 100661081 - 2⁶ = 100661017 is a prime.

It is a super-2 number, since 2×100661081² = 20265306456177122, which contains 22 as substring.

Together with 100661083, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (100661083) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50330540 + 50330541.

It is an arithmetic number, because the mean of its divisors is an integer number (50330541).

Almost surely, 2^100661081 is an apocalyptic number.

It is an amenable number.

100661081 is a deficient number, since it is larger than the sum of its proper divisors (1).

100661081 is an equidigital number, since it uses as much as digits as its factorization.

100661081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 288, while the sum is 23.

The square root of 100661081 is about 10032.9996013157. Note that the first 3 decimals coincide. The cubic root of 100661081 is about 465.1794597713.

The spelling of 100661081 in words is "one hundred million, six hundred sixty-one thousand, eighty-one".