1021002120109 has 2 divisors, whose sum is σ = 1021002120110. Its totient is φ = 1021002120108.

The previous prime is 1021002120031. The next prime is 1021002120119. The reversal of 1021002120109 is 9010212001201.

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., 562567502025 + 458434618084 = 750045^2 + 677078^2 .

It is a cyclic number.

It is not a de Polignac number, because 1021002120109 - 2²⁵ = 1020968565677 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1021002120119) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 510501060054 + 510501060055.

It is an arithmetic number, because the mean of its divisors is an integer number (510501060055).

Almost surely, 2^{1021002120109} is an apocalyptic number.

It is an amenable number.

1021002120109 is a deficient number, since it is larger than the sum of its proper divisors (1).

1021002120109 is an equidigital number, since it uses as much as digits as its factorization.

1021002120109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72, while the sum is 19.

The spelling of 1021002120109 in words is "one trillion, twenty-one billion, two million, one hundred twenty thousand, one hundred nine".