1021208408081 has 2 divisors, whose sum is σ = 1021208408082. Its totient is φ = 1021208408080.

The previous prime is 1021208408047. The next prime is 1021208408119. The reversal of 1021208408081 is 1808048021201.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 649126707856 + 372081700225 = 805684^2 + 609985^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1021208408081 is a prime.

It is a super-2 number, since 2×1021208408081² (a number of 25 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (1021208428081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 510604204040 + 510604204041.

It is an arithmetic number, because the mean of its divisors is an integer number (510604204041).

Almost surely, 2^{1021208408081} is an apocalyptic number.

It is an amenable number.

1021208408081 is a deficient number, since it is larger than the sum of its proper divisors (1).

1021208408081 is an equidigital number, since it uses as much as digits as its factorization.

1021208408081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8192, while the sum is 35.

The spelling of 1021208408081 in words is "one trillion, twenty-one billion, two hundred eight million, four hundred eight thousand, eighty-one".