2102121209989 has 2 divisors, whose sum is σ = 2102121209990. Its totient is φ = 2102121209988.

The previous prime is 2102121209971. The next prime is 2102121210017. The reversal of 2102121209989 is 9899021212012.

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., 1705766602500 + 396354607489 = 1306050^2 + 629567^2 .

It is a cyclic number.

It is not a de Polignac number, because 2102121209989 - 2³⁵ = 2067761471621 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2102121209939) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1051060604994 + 1051060604995.

It is an arithmetic number, because the mean of its divisors is an integer number (1051060604995).

Almost surely, 2^{2102121209989} is an apocalyptic number.

It is an amenable number.

2102121209989 is a deficient number, since it is larger than the sum of its proper divisors (1).

2102121209989 is an equidigital number, since it uses as much as digits as its factorization.

2102121209989 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 93312, while the sum is 46.

The spelling of 2102121209989 in words is "two trillion, one hundred two billion, one hundred twenty-one million, two hundred nine thousand, nine hundred eighty-nine".